diff --git a/admin-frontend-vue/src/api/envelope.ts b/admin-frontend-vue/src/api/envelope.ts
index 44766548..a2368b50 100644
--- a/admin-frontend-vue/src/api/envelope.ts
+++ b/admin-frontend-vue/src/api/envelope.ts
@@ -60,3 +60,36 @@ export function requestErrorMessage(error: unknown): string {
 export function loginRedirectTarget(location: { pathname: string; search: string }): string {
   return encodeURIComponent(`${location.pathname}${location.search}`)
 }
+
+/** 登录页统一入口；401 一律跳此路径。 */
+export const LOGIN_PATH = '/login'
+
+/** 当前 pathname 是否处于登录页（去掉可能携带的查询串后比较）。 */
+export function isLoginLocation(pathname: string): boolean {
+  if (typeof pathname !== 'string') return false
+  const queryAt = pathname.indexOf('?')
+  return (queryAt >= 0 ? pathname.slice(0, queryAt) : pathname) === LOGIN_PATH
+}
+
+/** 把请求 URL（相对或绝对）规整为相对路径，便于与登录入口比较。 */
+export function requestRelativePath(url: string): string {
+  if (typeof url !== 'string') return ''
+  const noQuery = url.split('?')[0]
+  const match = noQuery.match(/^[a-zA-Z][a-zA-Z0-9+.-]*:\/\/[^/]+(.*)$/)
+  return match ? match[1] : noQuery
+}
+
+/** 401 失败请求本身是否指向登录/认证端点（登录提交失败不应再被踢回登录页）。 */
+export function isAuthEndpointRequest(url: string | undefined): boolean {
+  return requestRelativePath(url || '') === LOGIN_PATH
+}
+
+/**
+ * 401 是否应执行“跳 /login”：已处于登录页或失败请求即登录端点时不应再跳，
+ * 否则会在登录页循环跳转或吞掉登录失败反馈。
+ */
+export function shouldRedirectUnauthorized(currentPathname: string, requestUrl?: string): boolean {
+  if (isLoginLocation(currentPathname)) return false
+  if (isAuthEndpointRequest(requestUrl)) return false
+  return true
+}
diff --git a/admin-frontend-vue/src/api/http.ts b/admin-frontend-vue/src/api/http.ts
index fee76c3c..92f21795 100644
--- a/admin-frontend-vue/src/api/http.ts
+++ b/admin-frontend-vue/src/api/http.ts
@@ -1,5 +1,5 @@
 import axios from 'axios'
-import { isUnauthorized, loginRedirectTarget } from './envelope'
+import { isUnauthorized, loginRedirectTarget, shouldRedirectUnauthorized } from './envelope'
 
 export { unwrap } from './envelope'
 
@@ -9,8 +9,10 @@ export const http = axios.create({
   timeout: 30_000,
 })
 
-function redirectToLogin(): void {
+function redirectToLogin(requestUrl?: string): void {
   if (typeof window === 'undefined') return
+  // 已在登录页或失败请求即登录端点时不再跳转，避免登录页循环与吞掉登录失败反馈。
+  if (!shouldRedirectUnauthorized(window.location.pathname, requestUrl)) return
   const target = loginRedirectTarget(window.location)
   window.location.assign(`/login?redirect=${target}`)
 }
@@ -18,11 +20,13 @@ function redirectToLogin(): void {
 http.interceptors.response.use(
   (response) => {
     // Java 未登录以 HTTP 200 + body.code=401 返回，需统一按未登录处理。
-    if (isUnauthorized(response.data)) redirectToLogin()
+    if (isUnauthorized(response.data)) redirectToLogin(response.config?.url)
     return response
   },
   (error) => {
-    if (error?.response?.status === 401 || isUnauthorized(error?.response?.data)) redirectToLogin()
+    if (error?.response?.status === 401 || isUnauthorized(error?.response?.data)) {
+      redirectToLogin(error?.config?.url)
+    }
     return Promise.reject(error)
   },
 )
diff --git a/admin-frontend-vue/tests/task-26.test.ts b/admin-frontend-vue/tests/task-26.test.ts
new file mode 100644
index 00000000..e647e4f4
--- /dev/null
+++ b/admin-frontend-vue/tests/task-26.test.ts
@@ -0,0 +1,72 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { readSource } from './helpers.ts'
+import {
+  isAuthEndpointRequest,
+  isLoginLocation,
+  shouldRedirectUnauthorized,
+} from '../src/api/envelope.ts'
+
+test('test_task_026_unauthorized_redirect_normal_primary_path', () => {
+  // 正常主路径：普通业务页内某受保护接口 401，应跳转登录（携带目标路径）。
+  assert.equal(
+    shouldRedirectUnauthorized('/admin-vue/account/users', '/api/admin/current-user'),
+    true,
+    '业务页内受保护请求 401 应触发跳登录',
+  )
+})
+
+test('test_task_026_unauthorized_redirect_normal_variant_input', () => {
+  // 正常变体：已经在登录页（含 redirect 查询）时任何 401 不再二次踢回，避免循环。
+  assert.equal(shouldRedirectUnauthorized('/login', '/api/admin/current-user'), false)
+  assert.equal(shouldRedirectUnauthorized('/login?redirect=%2Fadmin-vue%2Faccount%2Fusers', '/api/admin/current-user'), false)
+})
+
+test('test_task_026_unauthorized_redirect_normal_repeated_operation_is_idempotent', () => {
+  // 正常重复：纯函数重复求值结果稳定，无副作用。
+  const once = shouldRedirectUnauthorized('/login', '/login')
+  const twice = shouldRedirectUnauthorized('/login', '/login')
+  assert.equal(once, false)
+  assert.equal(twice, once)
+  assert.equal(isLoginLocation('/login?redirect=/x'), isLoginLocation('/login?redirect=/x'))
+})
+
+test('test_task_026_unauthorized_redirect_boundary_empty_input', () => {
+  // 边界空值：当前路径为空/请求 URL 缺省时不误判为登录场景，按应跳转处理。
+  assert.equal(shouldRedirectUnauthorized('', undefined), true)
+  assert.equal(shouldRedirectUnauthorized('/admin-vue/', ''), true)
+  assert.equal(isLoginLocation(''), false)
+  assert.equal(isAuthEndpointRequest(undefined), false)
+})
+
+test('test_task_026_unauthorized_redirect_boundary_single_item', () => {
+  // 边界单元素：401 请求本身是登录提交时不得再跳登录（否则吞掉登录失败反馈）。
+  assert.equal(shouldRedirectUnauthorized('/admin-vue/account/users', '/login'), false)
+  assert.equal(isAuthEndpointRequest('/login'), true)
+})
+
+test('test_task_026_unauthorized_redirect_boundary_limit_or_missing_field', () => {
+  // 边界上限/缺字段：登录端点支持绝对 URL 与带查询串的受保护请求两种形态。
+  assert.equal(isAuthEndpointRequest('http://api.aishufu.top/login'), true)
+  assert.equal(isAuthEndpointRequest('https://aishufu.top/login?device=web'), true)
+  assert.equal(shouldRedirectUnauthorized('/admin-vue/', '/api/admin/current-user?x=1'), true)
+  assert.equal(isAuthEndpointRequest('/api/admin/current-user?x=1'), false)
+})
+
+test('test_task_026_unauthorized_redirect_invalid_input_rejected', () => {
+  // 异常输入：非法/非字符串输入不抛错，且默认按“应跳转”处理而非误放行。
+  assert.equal(shouldRedirectUnauthorized(undefined as unknown as string, undefined), true)
+  assert.equal(shouldRedirectUnauthorized(null as unknown as string, null as unknown as string), true)
+  assert.equal(isAuthEndpointRequest(42 as unknown as string), false)
+  assert.equal(isLoginLocation('/admin-vue/login'), false)
+})
+
+test('test_task_026_unauthorized_redirect_dependency_failure_returns_actionable_message', () => {
+  // 依赖失败：http 层 success/error 两支都要先过守卫再带目标路径跳 /login。
+  const http = readSource('src/api/http.ts')
+  assert.match(http, /shouldRedirectUnauthorized/, '401 跳转必须经守卫避免登录页循环')
+  assert.match(http, /login\?redirect=/, '跳转仍携带目标路径参数')
+  assert.match(http, /interceptors\.response/)
+  assert.match(http, /response\.config\?\.url/, '成功分支以失败请求 URL 判定登录请求')
+  assert.match(http, /error\?\.config\?\.url|error\.config\.url/, '异常分支同样传入请求 URL')
+})