diff --git a/apps/admin-web/src/components/CityDistrictMultiSelect.tsx b/apps/admin-web/src/components/CityDistrictMultiSelect.tsx
new file mode 100644
index 0000000..779671c
--- /dev/null
+++ b/apps/admin-web/src/components/CityDistrictMultiSelect.tsx
@@ -0,0 +1,42 @@
+import { useMemo } from 'react';
+import { Select } from 'antd';
+import { getDistrictOptionsByCityCode } from '../lib/china-region';
+
+type Props = {
+  cityCode?: string | null;
+  value?: string[];
+  onChange?: (value: string[]) => void;
+  placeholder?: string;
+  disabled?: boolean;
+};
+
+/** 已选开城城市后，仅多选该市下区县（不再选省/市） */
+export default function CityDistrictMultiSelect({
+  cityCode,
+  value,
+  onChange,
+  placeholder,
+  disabled,
+}: Props) {
+  const options = useMemo(() => getDistrictOptionsByCityCode(cityCode), [cityCode]);
+  const ready = Boolean(cityCode) && options.length > 0;
+
+  return (
+    <Select
+      mode="multiple"
+      allowClear
+      showSearch
+      optionFilterProp="label"
+      value={value}
+      onChange={onChange}
+      disabled={disabled || !ready}
+      placeholder={
+        placeholder ??
+        (cityCode ? (ready ? '请选择区县（可多选）' : '该城市暂无区县数据') : '请先选择开城城市')
+      }
+      options={options}
+      style={{ width: '100%' }}
+      maxTagCount="responsive"
+    />
+  );
+}
diff --git a/apps/admin-web/src/components/CityPartnersPanel.tsx b/apps/admin-web/src/components/CityPartnersPanel.tsx
index 85c3f65..f7537fd 100644
--- a/apps/admin-web/src/components/CityPartnersPanel.tsx
+++ b/apps/admin-web/src/components/CityPartnersPanel.tsx
@@ -1,7 +1,6 @@
 import { useCallback, useEffect, useState } from 'react';
 import {
   Button,
-  Cascader,
   Checkbox,
   Drawer,
   Form,
@@ -27,8 +26,9 @@ import {
   type PartnerPermissionKey,
 } from '@dukang/shared-types';
 import { request, type Paginated } from '../lib/api';
-import { CHINA_REGION_OPTIONS } from '../lib/china-region';
+import { districtCodeLabel } from '../lib/china-region';
 import { fmtTime } from '../lib/constants';
+import CityDistrictMultiSelect from './CityDistrictMultiSelect';
 import PartnerSubAccountList from './PartnerSubAccountList';
 
 type PartnerRow = {
@@ -65,6 +65,7 @@ type PartnerDetail = PartnerRow & {
 
 type Props = {
   cityId: string;
+  cityCode?: string;
   maxPartnerCommissionRate?: number;
   onChanged?: () => void;
 };
@@ -102,7 +103,21 @@ function commissionSumError(
   return null;
 }
 
-export default function CityPartnersPanel({ cityId, maxPartnerCommissionRate = 0.05, onChanged }: Props) {
+function formatApiError(err: unknown): string | null {
+  if (err && typeof err === 'object' && 'errorFields' in err) return null;
+  if (!(err instanceof Error)) return '操作失败';
+  return err.message.replace(/\b(\d{6})\b/g, (code) => {
+    const label = districtCodeLabel(code);
+    return label !== code ? `${label}(${code})` : code;
+  });
+}
+
+export default function CityPartnersPanel({
+  cityId,
+  cityCode,
+  maxPartnerCommissionRate = 0.05,
+  onChanged,
+}: Props) {
   const [editForm] = Form.useForm();
   const [createForm] = Form.useForm();
   const [subForm] = Form.useForm();
@@ -156,29 +171,34 @@ export default function CityPartnersPanel({ cityId, maxPartnerCommissionRate = 0
 
   async function savePartner() {
     if (!detail) return;
-    const v = await editForm.validateFields();
-    const err = commissionSumError(
-      Number(v.orderCommissionRate ?? 0),
-      Number(v.redeemCommissionRate ?? 0),
-      maxPartnerCommissionRate,
-    );
-    if (err) {
-      message.error(err);
-      return;
+    try {
+      const v = await editForm.validateFields();
+      const err = commissionSumError(
+        Number(v.orderCommissionRate ?? 0),
+        Number(v.redeemCommissionRate ?? 0),
+        maxPartnerCommissionRate,
+      );
+      if (err) {
+        message.error(err);
+        return;
+      }
+      await request(`/admin/partners/${detail.id}`, {
+        method: 'PUT',
+        body: JSON.stringify({
+          ...v,
+          orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
+          redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
+          districtCodes: editScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
+        }),
+      });
+      message.success('已保存');
+      setDrawerOpen(false);
+      void loadPartners();
+      onChanged?.();
+    } catch (e) {
+      const msg = formatApiError(e);
+      if (msg) message.error(msg);
     }
-    await request(`/admin/partners/${detail.id}`, {
-      method: 'PUT',
-      body: JSON.stringify({
-        ...v,
-        orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
-        redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
-        districtCodes: editScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
-      }),
-    });
-    message.success('已保存');
-    setDrawerOpen(false);
-    void loadPartners();
-    onChanged?.();
   }
 
   async function deleteSubAccount(subId: string) {
@@ -264,8 +284,12 @@ export default function CityPartnersPanel({ cityId, maxPartnerCommissionRate = 0
                       <Select options={SCOPE_OPTIONS} onChange={(v) => setEditScopeType(v)} />
                     </Form.Item>
                     {editScopeType === CityPartnerScopeType.DISTRICT && (
-                      <Form.Item name="districtCodes" label="区县">
-                        <Cascader options={CHINA_REGION_OPTIONS} multiple changeOnSelect />
+                      <Form.Item
+                        name="districtCodes"
+                        label="区县"
+                        extra="仅可选当前开城城市下的区县；不可与其他区域合伙人重合"
+                      >
+                        <CityDistrictMultiSelect cityCode={cityCode} />
                       </Form.Item>
                     )}
                     <Space style={{ width: '100%' }} size="large">
@@ -319,30 +343,35 @@ export default function CityPartnersPanel({ cityId, maxPartnerCommissionRate = 0
       </Drawer>
 
       <Modal title="新建城市合伙人" open={createOpen} width={560} onCancel={() => setCreateOpen(false)} onOk={async () => {
-        const v = await createForm.validateFields();
-        const err = commissionSumError(
-          Number(v.orderCommissionRate ?? 0),
-          Number(v.redeemCommissionRate ?? 3),
-          maxPartnerCommissionRate,
-        );
-        if (err) {
-          message.error(err);
-          return;
+        try {
+          const v = await createForm.validateFields();
+          const err = commissionSumError(
+            Number(v.orderCommissionRate ?? 0),
+            Number(v.redeemCommissionRate ?? 3),
+            maxPartnerCommissionRate,
+          );
+          if (err) {
+            message.error(err);
+            return;
+          }
+          await request('/admin/partners', {
+            method: 'POST',
+            body: JSON.stringify({
+              ...v,
+              cityId,
+              orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
+              redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
+              districtCodes: createScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
+            }),
+          });
+          message.success('已创建');
+          setCreateOpen(false);
+          void loadPartners();
+          onChanged?.();
+        } catch (e) {
+          const msg = formatApiError(e);
+          if (msg) message.error(msg);
         }
-        await request('/admin/partners', {
-          method: 'POST',
-          body: JSON.stringify({
-            ...v,
-            cityId,
-            orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
-            redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
-            districtCodes: createScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
-          }),
-        });
-        message.success('已创建');
-        setCreateOpen(false);
-        void loadPartners();
-        onChanged?.();
       }}>
         <Form form={createForm} layout="vertical">
           <Form.Item name="companyName" label="公司名" rules={[{ required: true }]}><Input /></Form.Item>
@@ -353,8 +382,13 @@ export default function CityPartnersPanel({ cityId, maxPartnerCommissionRate = 0
             <Select options={SCOPE_OPTIONS} onChange={(v) => setCreateScopeType(v)} />
           </Form.Item>
           {createScopeType === CityPartnerScopeType.DISTRICT && (
-            <Form.Item name="districtCodes" label="区县" rules={[{ required: true }]}>
-              <Cascader options={CHINA_REGION_OPTIONS} multiple changeOnSelect />
+            <Form.Item
+              name="districtCodes"
+              label="区县"
+              rules={[{ required: true, message: '请选择至少一个区县' }]}
+              extra="仅可选当前开城城市下的区县；不可与其他区域合伙人重合"
+            >
+              <CityDistrictMultiSelect cityCode={cityCode} />
             </Form.Item>
           )}
           <Space style={{ width: '100%' }} size="large">
diff --git a/apps/admin-web/src/lib/china-region.ts b/apps/admin-web/src/lib/china-region.ts
index e6b3312..6612952 100644
--- a/apps/admin-web/src/lib/china-region.ts
+++ b/apps/admin-web/src/lib/china-region.ts
@@ -79,6 +79,33 @@ export function districtCodeToCityCode(districtCode: string): string {
   return `${districtCode.slice(0, 4)}00`;
 }
 
+export type DistrictOption = { value: string; label: string };
+
+/** 按开城城市 code（4 位或 6 位）取该市下区县列表 */
+export function getDistrictOptionsByCityCode(cityCode?: string | null): DistrictOption[] {
+  if (!cityCode?.trim()) return [];
+  const normalized = normalizeCityAdcode(cityCode.trim());
+  const prefix4 = normalized.slice(0, 4);
+
+  for (const province of regionData) {
+    for (const city of province.children ?? []) {
+      const cityValue = String(city.value);
+      const cityNorm = normalizeCityAdcode(cityValue);
+      if (cityNorm === normalized || cityValue === prefix4 || cityValue === cityCode.trim()) {
+        return (city.children ?? []).map((d) => ({
+          value: String(d.value),
+          label: String(d.label),
+        }));
+      }
+    }
+  }
+  return [];
+}
+
+export function districtCodeLabel(code: string): string {
+  return codeToText[code] || code;
+}
+
 export function parseRegionCodes(codes?: string[]): ParsedChinaRegion | null {
   if (!codes || codes.length < 3) return null;
   const [provinceCode, cityCode, districtCode] = codes;
diff --git a/apps/admin-web/src/pages/CitiesPage.tsx b/apps/admin-web/src/pages/CitiesPage.tsx
index 15721e7..d032a0c 100644
--- a/apps/admin-web/src/pages/CitiesPage.tsx
+++ b/apps/admin-web/src/pages/CitiesPage.tsx
@@ -274,6 +274,7 @@ export default function CitiesPage() {
                 children: detail?.id ? (
                   <CityPartnersPanel
                     cityId={String(detail.id)}
+                    cityCode={detail.code != null ? String(detail.code) : undefined}
                     maxPartnerCommissionRate={
                       detail.maxPartnerCommissionRate != null
                         ? Number(detail.maxPartnerCommissionRate)
diff --git a/apps/admin-web/src/pages/CityPartnersPage.tsx b/apps/admin-web/src/pages/CityPartnersPage.tsx
index 7cf0cb2..af4671e 100644
--- a/apps/admin-web/src/pages/CityPartnersPage.tsx
+++ b/apps/admin-web/src/pages/CityPartnersPage.tsx
@@ -3,7 +3,6 @@ import { Link } from 'react-router-dom';
 import {
   Alert,
   Button,
-  Cascader,
   Checkbox,
   Descriptions,
   Drawer,
@@ -32,9 +31,10 @@ import {
   type PartnerPermissionKey,
 } from '@dukang/shared-types';
 import { request, type Paginated } from '../lib/api';
-import { CHINA_REGION_OPTIONS } from '../lib/china-region';
+import { districtCodeLabel } from '../lib/china-region';
 import { ADMIN_OPTIONS_PAGE_SIZE, fmtTime } from '../lib/constants';
 import { useAdminList } from '../lib/useAdminList';
+import CityDistrictMultiSelect from '../components/CityDistrictMultiSelect';
 import PartnerSubAccountList, { type PartnerSubAccountRow } from '../components/PartnerSubAccountList';
 
 type SubRow = PartnerSubAccountRow;
@@ -108,6 +108,15 @@ function commissionSumError(orderPercent: number, redeemPercent: number, maxRate
   return null;
 }
 
+function formatApiError(err: unknown): string | null {
+  if (err && typeof err === 'object' && 'errorFields' in err) return null;
+  if (!(err instanceof Error)) return '操作失败';
+  return err.message.replace(/\b(\d{6})\b/g, (code) => {
+    const label = districtCodeLabel(code);
+    return label !== code ? `${label}(${code})` : code;
+  });
+}
+
 export default function CityPartnersPage() {
   const [filterForm] = Form.useForm();
   const [editForm] = Form.useForm();
@@ -138,6 +147,7 @@ export default function CityPartnersPage() {
   const [editScopeType, setEditScopeType] = useState<CityPartnerScopeType>(CityPartnerScopeType.CITY_WIDE);
   const [maxCommissionRate, setMaxCommissionRate] = useState(0.05);
   const [createMaxRate, setCreateMaxRate] = useState(0.05);
+  const [createCityCode, setCreateCityCode] = useState<string | undefined>();
 
   const loadCities = useCallback(async () => {
     const res = await request<Paginated<CityOption>>(`/admin/cities?pageSize=${ADMIN_OPTIONS_PAGE_SIZE}`);
@@ -148,6 +158,10 @@ export default function CityPartnersPage() {
     void loadCities();
   }, [loadCities]);
 
+  const editCityCode = detail?.cityId
+    ? cities.find((c) => c.id === detail.cityId)?.code
+    : undefined;
+
   async function openPartner(id: string) {
     const d = await request<PartnerDetail>(`/admin/partners/${id}`);
     setDetail(d);
@@ -174,28 +188,33 @@ export default function CityPartnersPage() {
 
   async function savePartner() {
     if (!detail) return;
-    const v = await editForm.validateFields();
-    const err = commissionSumError(
-      Number(v.orderCommissionRate ?? 0),
-      Number(v.redeemCommissionRate ?? 0),
-      maxCommissionRate,
-    );
-    if (err) {
-      message.error(err);
-      return;
+    try {
+      const v = await editForm.validateFields();
+      const err = commissionSumError(
+        Number(v.orderCommissionRate ?? 0),
+        Number(v.redeemCommissionRate ?? 0),
+        maxCommissionRate,
+      );
+      if (err) {
+        message.error(err);
+        return;
+      }
+      await request(`/admin/partners/${detail.id}`, {
+        method: 'PUT',
+        body: JSON.stringify({
+          ...v,
+          orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
+          redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
+          districtCodes: editScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
+        }),
+      });
+      message.success('已保存');
+      setDrawerOpen(false);
+      void reload();
+    } catch (e) {
+      const msg = formatApiError(e);
+      if (msg) message.error(msg);
     }
-    await request(`/admin/partners/${detail.id}`, {
-      method: 'PUT',
-      body: JSON.stringify({
-        ...v,
-        orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
-        redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
-        districtCodes: editScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
-      }),
-    });
-    message.success('已保存');
-    setDrawerOpen(false);
-    void reload();
   }
 
   async function refreshPartnerContext(parentId: string) {
@@ -232,6 +251,9 @@ export default function CityPartnersPage() {
   }
 
   async function onCreateCityChange(cityId: string) {
+    createForm.setFieldsValue({ districtCodes: undefined });
+    const matched = cities.find((c) => c.id === cityId);
+    setCreateCityCode(matched?.code);
     const cityRes = await request<{ maxPartnerCommissionRate?: number }>(`/admin/cities/${cityId}`);
     setCreateMaxRate(Number(cityRes.maxPartnerCommissionRate ?? 0.05));
   }
@@ -302,6 +324,7 @@ export default function CityPartnersPage() {
             });
             setCreateScopeType(CityPartnerScopeType.CITY_WIDE);
             setCreateMaxRate(0.05);
+            setCreateCityCode(undefined);
             setCreateOpen(true);
           }}
         >
@@ -450,8 +473,12 @@ export default function CityPartnersPage() {
                         <Select options={SCOPE_OPTIONS} onChange={(v) => setEditScopeType(v)} />
                       </Form.Item>
                       {editScopeType === CityPartnerScopeType.DISTRICT && (
-                        <Form.Item name="districtCodes" label="区县">
-                          <Cascader options={CHINA_REGION_OPTIONS} multiple changeOnSelect />
+                        <Form.Item
+                          name="districtCodes"
+                          label="区县"
+                          extra="仅可选当前开城城市下的区县；不可与其他区域合伙人重合"
+                        >
+                          <CityDistrictMultiSelect cityCode={editCityCode} />
                         </Form.Item>
                       )}
                       <Space style={{ width: '100%' }} size="large">
@@ -505,29 +532,34 @@ export default function CityPartnersPage() {
         width={560}
         onCancel={() => setCreateOpen(false)}
         onOk={async () => {
-          const v = await createForm.validateFields();
-          const err = commissionSumError(
-            Number(v.orderCommissionRate ?? 0),
-            Number(v.redeemCommissionRate ?? 3),
-            createMaxRate,
-          );
-          if (err) {
-            message.error(err);
-            return;
+          try {
+            const v = await createForm.validateFields();
+            const err = commissionSumError(
+              Number(v.orderCommissionRate ?? 0),
+              Number(v.redeemCommissionRate ?? 3),
+              createMaxRate,
+            );
+            if (err) {
+              message.error(err);
+              return;
+            }
+            await request('/admin/partners', {
+              method: 'POST',
+              body: JSON.stringify({
+                ...v,
+                orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
+                redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
+                districtCodes:
+                  createScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
+              }),
+            });
+            message.success('已创建');
+            setCreateOpen(false);
+            void reload();
+          } catch (e) {
+            const msg = formatApiError(e);
+            if (msg) message.error(msg);
           }
-          await request('/admin/partners', {
-            method: 'POST',
-            body: JSON.stringify({
-              ...v,
-              orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
-              redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
-              districtCodes:
-                createScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
-            }),
-          });
-          message.success('已创建');
-          setCreateOpen(false);
-          void reload();
         }}
       >
         <Form form={createForm} layout="vertical">
@@ -555,8 +587,13 @@ export default function CityPartnersPage() {
             <Select options={SCOPE_OPTIONS} onChange={(v) => setCreateScopeType(v)} />
           </Form.Item>
           {createScopeType === CityPartnerScopeType.DISTRICT && (
-            <Form.Item name="districtCodes" label="区县" rules={[{ required: true }]}>
-              <Cascader options={CHINA_REGION_OPTIONS} multiple changeOnSelect />
+            <Form.Item
+              name="districtCodes"
+              label="区县"
+              rules={[{ required: true, message: '请选择至少一个区县' }]}
+              extra="仅可选当前开城城市下的区县；不可与其他区域合伙人重合"
+            >
+              <CityDistrictMultiSelect cityCode={createCityCode} />
             </Form.Item>
           )}
           <Space style={{ width: '100%' }} size="large">
diff --git a/apps/admin-web/src/pages/PartnersPage.tsx b/apps/admin-web/src/pages/PartnersPage.tsx
index e286ed8..170cec2 100644
--- a/apps/admin-web/src/pages/PartnersPage.tsx
+++ b/apps/admin-web/src/pages/PartnersPage.tsx
@@ -1,7 +1,6 @@
 import { useCallback, useEffect, useState } from 'react';
 import {
   Button,
-  Cascader,
   Drawer,
   Form,
   Input,
@@ -24,9 +23,10 @@ import {
   type PartnerPermissionKey,
 } from '@dukang/shared-types';
 import { request, type Paginated } from '../lib/api';
-import { CHINA_REGION_OPTIONS } from '../lib/china-region';
+import { districtCodeLabel } from '../lib/china-region';
 import { ADMIN_OPTIONS_PAGE_SIZE, fmtTime } from '../lib/constants';
 import { useAdminList } from '../lib/useAdminList';
+import CityDistrictMultiSelect from '../components/CityDistrictMultiSelect';
 
 type Row = {
   id: string;
@@ -102,6 +102,18 @@ export default function PartnersPage() {
   const [editScopeType, setEditScopeType] = useState<CityPartnerScopeType>(CityPartnerScopeType.CITY_WIDE);
   const [createCityId, setCreateCityId] = useState<string | undefined>();
 
+  const createCityCode = createCityId ? cities.find((c) => c.id === createCityId)?.code : undefined;
+  const editCityCode = detail?.cityId ? cities.find((c) => c.id === detail.cityId)?.code : undefined;
+
+  function formatApiError(err: unknown): string | null {
+    if (err && typeof err === 'object' && 'errorFields' in err) return null;
+    if (!(err instanceof Error)) return '操作失败';
+    return err.message.replace(/\b(\d{6})\b/g, (code) => {
+      const label = districtCodeLabel(code);
+      return label !== code ? `${label}(${code})` : code;
+    });
+  }
+
   const loadCities = useCallback(async () => {
     const res = await request<Paginated<CityOption>>(`/admin/cities?pageSize=${ADMIN_OPTIONS_PAGE_SIZE}`);
     setCities(res.items);
@@ -142,17 +154,22 @@ export default function PartnersPage() {
 
   async function savePartner() {
     if (!detail) return;
-    const v = await editForm.validateFields();
-    const body = {
-      ...v,
-      orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
-      redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
-      districtCodes: editScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
-    };
-    await request(`/admin/partners/${detail.id}`, { method: 'PUT', body: JSON.stringify(body) });
-    message.success('已保存');
-    setDrawerOpen(false);
-    void reload();
+    try {
+      const v = await editForm.validateFields();
+      const body = {
+        ...v,
+        orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
+        redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
+        districtCodes: editScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
+      };
+      await request(`/admin/partners/${detail.id}`, { method: 'PUT', body: JSON.stringify(body) });
+      message.success('已保存');
+      setDrawerOpen(false);
+      void reload();
+    } catch (e) {
+      const msg = formatApiError(e);
+      if (msg) message.error(msg);
+    }
   }
 
   const columns: ColumnsType<Row> = [
@@ -231,8 +248,12 @@ export default function PartnersPage() {
                       <Select options={SCOPE_OPTIONS} onChange={(v) => setEditScopeType(v)} />
                     </Form.Item>
                     {editScopeType === CityPartnerScopeType.DISTRICT && (
-                      <Form.Item name="districtCodes" label="区县">
-                        <Cascader options={CHINA_REGION_OPTIONS} multiple changeOnSelect />
+                      <Form.Item
+                        name="districtCodes"
+                        label="区县"
+                        extra="仅可选当前开城城市下的区县；不可与其他区域合伙人重合"
+                      >
+                        <CityDistrictMultiSelect cityCode={editCityCode} />
                       </Form.Item>
                     )}
                     <Space style={{ width: '100%' }} size="large">
@@ -286,27 +307,36 @@ export default function PartnersPage() {
         width={560}
         onCancel={() => setCreateOpen(false)}
         onOk={async () => {
-          const v = await createForm.validateFields();
-          await request('/admin/partners', {
-            method: 'POST',
-            body: JSON.stringify({
-              ...v,
-              orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
-              redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
-              districtCodes: createScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
-            }),
-          });
-          message.success('已创建');
-          setCreateOpen(false);
-          createForm.resetFields();
-          void reload();
+          try {
+            const v = await createForm.validateFields();
+            await request('/admin/partners', {
+              method: 'POST',
+              body: JSON.stringify({
+                ...v,
+                orderCommissionRate: Number(v.orderCommissionRate ?? 0) / 100,
+                redeemCommissionRate: Number(v.redeemCommissionRate ?? 3) / 100,
+                districtCodes: createScopeType === CityPartnerScopeType.DISTRICT ? flattenDistrictCodes(v.districtCodes) : undefined,
+              }),
+            });
+            message.success('已创建');
+            setCreateOpen(false);
+            createForm.resetFields();
+            void reload();
+          } catch (e) {
+            const msg = formatApiError(e);
+            if (msg) message.error(msg);
+          }
         }}
       >
         <Form form={createForm} layout="vertical" initialValues={{ orderCommissionRate: 0, redeemCommissionRate: 3, scopeType: CityPartnerScopeType.CITY_WIDE }}>
           <Form.Item name="cityId" label="开城城市" rules={[{ required: true }]}>
             <Select
               options={cities.map((c) => ({ value: c.id, label: `${c.name} (${c.code})` }))}
-              onChange={(id) => { setCreateCityId(id); void loadWarehouses(id); }}
+              onChange={(id) => {
+                setCreateCityId(id);
+                createForm.setFieldsValue({ districtCodes: undefined });
+                void loadWarehouses(id);
+              }}
             />
           </Form.Item>
           <Form.Item name="companyName" label="公司名" rules={[{ required: true }]}><Input /></Form.Item>
@@ -317,8 +347,13 @@ export default function PartnersPage() {
             <Select options={SCOPE_OPTIONS} onChange={(v) => setCreateScopeType(v)} />
           </Form.Item>
           {createScopeType === CityPartnerScopeType.DISTRICT && (
-            <Form.Item name="districtCodes" label="区县" rules={[{ required: true }]}>
-              <Cascader options={CHINA_REGION_OPTIONS} multiple changeOnSelect />
+            <Form.Item
+              name="districtCodes"
+              label="区县"
+              rules={[{ required: true, message: '请选择至少一个区县' }]}
+              extra="仅可选当前开城城市下的区县；不可与其他区域合伙人重合"
+            >
+              <CityDistrictMultiSelect cityCode={createCityCode} />
             </Form.Item>
           )}
           <Space style={{ width: '100%' }} size="large">
diff --git a/packages/domain/src/city-partner.test.ts b/packages/domain/src/city-partner.test.ts
index b59ba13..17e3efe 100644
--- a/packages/domain/src/city-partner.test.ts
+++ b/packages/domain/src/city-partner.test.ts
@@ -63,10 +63,21 @@ describe('validatePartnerCityBinding', () => {
 
   it('rejects overlapping district codes', () => {
     const result = validatePartnerCityBinding(
-      [{ id: '1', partnerAccountId: '10', scopeType: 'DISTRICT', districtCodes: ['410105'] }],
+      [
+        {
+          id: '1',
+          partnerAccountId: '10',
+          scopeType: 'DISTRICT',
+          districtCodes: ['410105'],
+          companyName: '甲公司',
+        },
+      ],
       { partnerAccountId: '11', scopeType: 'DISTRICT', districtCodes: ['410105'] },
     );
     expect(result.ok).toBe(false);
+    expect(result.message).toContain('区域重合');
+    expect(result.message).toContain('甲公司');
+    expect(result.occupiedCodes).toEqual(['410105']);
   });
 
   it('allows valid district binding', () => {
diff --git a/packages/domain/src/city-partner.ts b/packages/domain/src/city-partner.ts
index 3eafdb8..8dbdb8d 100644
--- a/packages/domain/src/city-partner.ts
+++ b/packages/domain/src/city-partner.ts
@@ -7,6 +7,8 @@ export interface PartnerCityBindingInput {
   scopeType: CityPartnerScopeType;
   districtCodes?: string[] | null;
   bindingStatus?: CityPartnerStatus;
+  /** 仅用于重合报错文案 */
+  companyName?: string | null;
 }
 
 export interface PartnerCityResolveRef {
@@ -20,6 +22,7 @@ export interface PartnerCityResolveRef {
 export interface PartnerCityValidationResult {
   ok: boolean;
   message?: string;
+  occupiedCodes?: string[];
 }
 
 function normalizeDistrictCodes(codes?: string[] | null): string[] {
@@ -98,18 +101,25 @@ export function validatePartnerCityBinding(
     return { ok: false, message: '区域合伙人须至少选择一个区县' };
   }
 
-  const occupied = new Set<string>();
+  const occupiedBy = new Map<string, string>();
   for (const row of others) {
     if (row.scopeType !== 'DISTRICT') continue;
+    const owner = row.companyName?.trim() || '其他区域合伙人';
     for (const code of normalizeDistrictCodes(row.districtCodes)) {
-      occupied.add(code);
+      if (!occupiedBy.has(code)) occupiedBy.set(code, owner);
     }
   }
 
-  for (const code of districts) {
-    if (occupied.has(code)) {
-      return { ok: false, message: `区县 ${code} 已被其他区域合伙人占用` };
-    }
+  const overlaps = districts.filter((code) => occupiedBy.has(code));
+  if (overlaps.length) {
+    const detail = overlaps
+      .map((code) => `${code}（${occupiedBy.get(code)}）`)
+      .join('、');
+    return {
+      ok: false,
+      message: `区域重合：以下区县已被占用，请改选其他区县 — ${detail}`,
+      occupiedCodes: overlaps,
+    };
   }
 
   return { ok: true };
diff --git a/server/dukang-api/src/modules/city-scope/partner-city.service.ts b/server/dukang-api/src/modules/city-scope/partner-city.service.ts
index 69e94e4..59c5ace 100644
--- a/server/dukang-api/src/modules/city-scope/partner-city.service.ts
+++ b/server/dukang-api/src/modules/city-scope/partner-city.service.ts
@@ -87,6 +87,7 @@ export class PartnerCityService {
         partnerAccountId: r.id.toString(),
         scopeType: r.scopeType as CityPartnerScopeType,
         districtCodes: this.parseDistrictCodes(r.districtCodes),
+        companyName: r.companyName,
       })),
       {
         partnerAccountId: input.partnerAccountId ?? 'new',