diff --git a/frontend/src/pages/usr/UserDetail/index.tsx b/frontend/src/pages/usr/UserDetail/index.tsx
index 15245e3..2ff9ed0 100644
--- a/frontend/src/pages/usr/UserDetail/index.tsx
+++ b/frontend/src/pages/usr/UserDetail/index.tsx
@@ -13,7 +13,6 @@ import {
   MODE_EDIT,
   MSG_CREATE_SUCCESS,
   MSG_EDIT_SUCCESS,
-  MSG_ERR_USER_NOT_FOUND,
   MSG_LOAD_DETAIL_FAIL,
   MSG_CANCEL_CONFIRM,
   PATH_USER_LIST,
@@ -54,7 +53,6 @@ export default function UserDetailPage() {
     loading,
     submitting,
     loadFailed,
-    notFound,
     selectEmployee,
     togglePermission,
     toggleAll,
@@ -107,21 +105,10 @@ export default function UserDetailPage() {
     selectEmployee(value);
   };
 
-  // edit 详情不存在（40401）：返回列表入口（spec § 4）
-  if (notFound) {
-    return (
-      <div className={styles.page}>
-        <div className={styles.loadError} data-testid="userdetail-notfound">
-          <span className={styles.loadErrorText}>{MSG_ERR_USER_NOT_FOUND}</span>
-          <Button type="primary" onClick={() => navigate(PATH_USER_LIST)}>
-            {TEXT_BACK_TO_LIST}
-          </Button>
-        </div>
-      </div>
-    );
-  }
-
-  // 预取/详情取数失败：重试入口（spec § 4 loadError）
+  // 预取/详情取数失败：整页重试入口（spec § 4 loadError）。
+  // edit 态额外给「返回列表」——edit 预填只能来自列表行经 navigate state 透传的
+  // presetUser（无 by-id 读端点，详见 useUserDetail），缺 state 时重试仍会回到 loadError，
+  // 需经列表双击重新携带 state 进入，故提供返回列表入口（spec § 4「edit 详情失败给整页重试或返回列表」）。
   if (loadFailed) {
     return (
       <div className={styles.page}>
@@ -130,6 +117,11 @@ export default function UserDetailPage() {
           <Button type="primary" onClick={() => reload()}>
             {TEXT_RETRY}
           </Button>
+          {mode === MODE_EDIT && (
+            <Button onClick={() => navigate(PATH_USER_LIST)}>
+              {TEXT_BACK_TO_LIST}
+            </Button>
+          )}
         </div>
       </div>
     );
diff --git a/frontend/src/pages/usr/UserDetail/useUserDetail.ts b/frontend/src/pages/usr/UserDetail/useUserDetail.ts
index f23d699..e36b224 100644
--- a/frontend/src/pages/usr/UserDetail/useUserDetail.ts
+++ b/frontend/src/pages/usr/UserDetail/useUserDetail.ts
@@ -4,7 +4,6 @@ import { App as AntdApp } from 'antd';
 import {
   createUser,
   updateUser,
-  getUserDetail,
   listEmployees,
   listPermissions,
 } from '../../../api/usrApi';
@@ -64,7 +63,6 @@ export interface UseUserDetailReturn {
   submitting: boolean;
   error: ApiError | null;
   loadFailed: boolean;
-  notFound: boolean;
   setField(name: keyof UserFormValues, value: unknown): void;
   selectEmployee(value: number | null): void;
   togglePermission(id: number, checked: boolean): void;
@@ -87,7 +85,6 @@ export function useUserDetail(args: UseUserDetailArgs): UseUserDetailReturn {
   const [submitting, setSubmitting] = useState(false);
   const [error, setError] = useState<ApiError | null>(null);
   const [loadFailed, setLoadFailed] = useState(false);
-  const [notFound, setNotFound] = useState(false);
 
   const employeesRef = useRef<EmployeeOption[]>(employees);
   employeesRef.current = employees;
@@ -110,7 +107,6 @@ export function useUserDetail(args: UseUserDetailArgs): UseUserDetailReturn {
   const runLoad = useCallback(async () => {
     setLoading(true);
     setLoadFailed(false);
-    setNotFound(false);
     try {
       const [emps, perms] = await Promise.all([listEmployees(), listPermissions()]);
       if (!mountedRef.current) return;
@@ -120,21 +116,18 @@ export function useUserDetail(args: UseUserDetailArgs): UseUserDetailReturn {
       if (mode === 'edit') {
         if (presetUser) {
           initFromVo(presetUser);
-        } else if (userId != null) {
-          const vo = await getUserDetail({
-            queryField: '用户号',
-            queryValue: String(userId),
-          });
+        } else {
+          // FE-04: edit 预填只能来自 FE-03 经 navigate state 透传的列表行（presetUser）。
+          // 路由 :id 是用户主键，而唯一读端点 GET /api/usr/users 的 queryField 无主键选项
+          // （docs/05 REQ-USR-003），故不能按主键去查「用户号」列——在真实后端必然返回空、
+          // 误报 40401，无法满足编辑预填（BR17 / REQ-USR-002 验收）。
+          // 缺 presetUser（如直接访问 URL / 刷新丢失 state）时按 loadError 处理，
+          // 由页面给出「返回列表」重试入口，重新经列表双击携带 state 进入。
           if (!mountedRef.current) return;
-          if (vo) {
-            initFromVo(vo);
-          } else {
-            // 详情不存在：交由页面按 40401 路径处理（返回列表入口）
-            setNotFound(true);
-            messageRef.current.error(MSG_ERR_USER_NOT_FOUND);
-            setLoading(false);
-            return;
-          }
+          setLoading(false);
+          setLoadFailed(true);
+          messageRef.current.error(MSG_LOAD_DETAIL_FAIL);
+          return;
         }
       } else {
         setFormValues({ ...CREATE_DEFAULTS });
@@ -259,7 +252,6 @@ export function useUserDetail(args: UseUserDetailArgs): UseUserDetailReturn {
     submitting,
     error,
     loadFailed,
-    notFound,
     setField,
     selectEmployee,
     togglePermission,
diff --git a/frontend/src/pages/usr/UserList/index.tsx b/frontend/src/pages/usr/UserList/index.tsx
index 1fb4064..64d1271 100644
--- a/frontend/src/pages/usr/UserList/index.tsx
+++ b/frontend/src/pages/usr/UserList/index.tsx
@@ -33,7 +33,12 @@ export default function UserListPage() {
   const [selectedRowKey, setSelectedRowKey] = useState<number | null>(null);
 
   const handleRowDoubleClick = (row: UserVO) => {
-    navigate('/usr/users/' + row.id); // BR12
+    // BR12: 进入编辑单据。列表行 UserVO 已含单据预填所需全部字段，
+    // 经 navigate state 透传给详情页走 presetUser 分支；
+    // 不能仅靠 :id（路由 :id 为用户主键，而读端点 GET /api/usr/users 的 queryField
+    // 无主键选项，按主键去查「用户号」列在真实后端必然返回空 → 误报 40401），
+    // 详见 FE-04 / docs/05 REQ-USR-002。
+    navigate('/usr/users/' + row.id, { state: { user: row } });
   };
 
   return (
diff --git a/frontend/tests/unit/UserDetailPage.test.tsx b/frontend/tests/unit/UserDetailPage.test.tsx
index b86f09f..ac7a023 100644
--- a/frontend/tests/unit/UserDetailPage.test.tsx
+++ b/frontend/tests/unit/UserDetailPage.test.tsx
@@ -69,7 +69,13 @@ function LocationProbe() {
   return <div data-testid="loc">{loc.pathname}</div>;
 }
 
-function renderPage(entry: string) {
+// FE-04: edit 单据预填来自 FE-03 经 navigate state 透传的列表行（presetUser）。
+// 测试入口可携带 state.user 复刻该数据流（路由 :id 仅为主键，无 by-id 读端点，
+// 不能按主键查「用户号」列——详见 useUserDetail / docs/05 REQ-USR-002/003）。
+function renderPage(entry: string, presetUser?: UserVO) {
+  const initialEntry = presetUser
+    ? { pathname: entry, state: { user: presetUser } }
+    : entry;
   return renderShell(
     <>
       <LocationProbe />
@@ -80,7 +86,7 @@ function renderPage(entry: string) {
       </Routes>
     </>,
     {
-      initialEntries: [entry],
+      initialEntries: [initialEntry],
       preloadedAuth: {
         token: 't',
         user: { id: 1, sUserName: '朱子纯', sUserType: '超级管理员', sLanguage: '中文' },
@@ -148,22 +154,20 @@ describe('UserDetailPage 集成', () => {
     expect(await screen.findByText('用户名已存在，请更换')).toBeInTheDocument();
   });
 
-  it('edit mode prefills from getUserDetail and username disabled', async () => {
-    mockedDetail.mockResolvedValue(makeVo());
-    renderPage('/usr/users/7');
-    await waitFor(() => expect(mockedDetail).toHaveBeenCalled());
+  it('edit mode prefills from navigate state (presetUser) and username disabled', async () => {
+    // FE-04: edit 预填走 FE-03 经 navigate state 透传的列表行，不再按主键查列表端点
+    renderPage('/usr/users/7', makeVo());
     await waitFor(() =>
       expect((screen.getByTestId('field-username') as HTMLInputElement).value).toBe('zhangsan'),
     );
+    expect(mockedDetail).not.toHaveBeenCalled();
     expect(screen.getByTestId('field-username')).toBeDisabled();
   });
 
   it('edit submit success navigates to /usr/users with 保存成功', async () => {
     const user = userEvent.setup();
-    mockedDetail.mockResolvedValue(makeVo());
     mockedUpdate.mockResolvedValue({ id: 7 });
-    renderPage('/usr/users/7');
-    await waitFor(() => expect(mockedDetail).toHaveBeenCalled());
+    renderPage('/usr/users/7', makeVo());
     await waitFor(() =>
       expect((screen.getByTestId('field-username') as HTMLInputElement).value).toBe('zhangsan'),
     );
@@ -188,9 +192,11 @@ describe('UserDetailPage 集成', () => {
 
   it('新增 navigates to /usr/users/new', async () => {
     const user = userEvent.setup();
-    mockedDetail.mockResolvedValue(makeVo());
-    renderPage('/usr/users/7');
-    await waitFor(() => expect(mockedDetail).toHaveBeenCalled());
+    // edit 经 navigate state 预填后，工具栏「新增」跳 /usr/users/new（BR14）
+    renderPage('/usr/users/7', makeVo());
+    await waitFor(() =>
+      expect((screen.getByTestId('field-username') as HTMLInputElement).value).toBe('zhangsan'),
+    );
     await user.click(screen.getByTestId('btn-new'));
     await waitFor(() => expect(screen.getByTestId('loc').textContent).toBe('/usr/users/new'));
   });
@@ -205,12 +211,16 @@ describe('UserDetailPage 集成', () => {
     await waitFor(() => expect(screen.queryByTestId('userdetail-loaderror')).toBeNull());
   });
 
-  it('edit 40401 offers 返回列表', async () => {
-    mockedDetail.mockResolvedValue(null);
+  it('edit without navigate state shows loadError offering 点击重试 + 返回列表', async () => {
+    // FE-04 B1 fix: edit 缺 presetUser（直接访问 URL / 刷新丢 state）→ loadError，
+    // 整页给「点击重试」与「返回列表」两个入口（spec § 4 loadError）。
     renderPage('/usr/users/7');
-    expect(await screen.findByText('该用户不存在或已被删除')).toBeInTheDocument();
+    const loadError = await screen.findByTestId('userdetail-loaderror');
+    expect(within(loadError).getByText('点击重试')).toBeInTheDocument();
+    expect(within(loadError).getByText('返回列表')).toBeInTheDocument();
+    expect(mockedDetail).not.toHaveBeenCalled();
     const user = userEvent.setup();
-    await user.click(screen.getByText('返回列表'));
+    await user.click(within(loadError).getByText('返回列表'));
     await waitFor(() => expect(screen.getByTestId('loc').textContent).toBe('/usr/users'));
   });
 });
diff --git a/frontend/tests/unit/renderShell.tsx b/frontend/tests/unit/renderShell.tsx
index f6c0b01..f4d7d4f 100644
--- a/frontend/tests/unit/renderShell.tsx
+++ b/frontend/tests/unit/renderShell.tsx
@@ -4,6 +4,10 @@ import type { ReactElement } from 'react';
 import { render } from '@testing-library/react';
 import { Provider } from 'react-redux';
 import { MemoryRouter } from 'react-router-dom';
+
+// react-router-dom 未公开 re-export InitialEntry，这里按其 MemoryRouter 接受的形态本地声明：
+// 纯路径字符串，或携带 navigate state 的 Partial<Location>（FE-04 edit 预填数据流需要）。
+type ShellInitialEntry = string | { pathname: string; search?: string; hash?: string; state?: unknown };
 import { App as AntdApp, ConfigProvider } from 'antd';
 import zhCN from 'antd/locale/zh_CN';
 import { configureStore } from '@reduxjs/toolkit';
@@ -21,7 +25,9 @@ export function makeShellStore(preloadedAuth?: Partial<AuthState>) {
 }
 
 export interface RenderShellOptions {
-  initialEntries?: string[];
+  // FE-04: 允许传 Partial<Location>（携带 navigate state），用于复刻 edit 单据经
+  // navigate state 透传 presetUser 的数据流，不仅限纯路径字符串。
+  initialEntries?: ShellInitialEntry[];
   preloadedAuth?: Partial<AuthState>;
   store?: ReturnType<typeof makeShellStore>;
 }
diff --git a/frontend/tests/unit/useUserDetail.test.tsx b/frontend/tests/unit/useUserDetail.test.tsx
index 2d374e2..351d05a 100644
--- a/frontend/tests/unit/useUserDetail.test.tsx
+++ b/frontend/tests/unit/useUserDetail.test.tsx
@@ -118,17 +118,17 @@ describe('useUserDetail 状态机', () => {
     expect(mockedDetail).not.toHaveBeenCalled();
   });
 
-  it('edit mode prefills from getUserDetail and pre-checks permissions', async () => {
-    mockedDetail.mockResolvedValue(makeVo());
+  it('edit mode without presetUser sets loadFailed without calling getUserDetail', async () => {
+    // FE-04 B1 fix: 路由 :id 为用户主键，无 by-id 读端点（docs/05 REQ-USR-003），
+    // 不能按主键查列表端点；缺 presetUser（直接访问 URL / 刷新丢 state）时按 loadError 处理，
+    // 由页面给出「返回列表」恢复入口。
     const { result } = renderHook(
       () => useUserDetail({ mode: 'edit', userId: 7 }),
       { wrapper },
     );
     await waitFor(() => expect(result.current.loading).toBe(false));
-    expect(mockedDetail).toHaveBeenCalled();
-    expect(result.current.formValues.sUserName).toBe('zhangsan');
-    expect(result.current.formValues.sUserType).toBe('超级管理员');
-    expect(result.current.formValues.sLanguage).toBe('英文');
+    expect(result.current.loadFailed).toBe(true);
+    expect(mockedDetail).not.toHaveBeenCalled();
   });
 
   it('edit mode with presetUser skips getUserDetail', async () => {