diff --git a/frontend/src/api/audit.ts b/frontend/src/api/audit.ts
index 10c18cb..85f1d15 100644
--- a/frontend/src/api/audit.ts
+++ b/frontend/src/api/audit.ts
@@ -1,4 +1,4 @@
-import request from './request'
+import type { ApiResponse, PaginatedData } from '@/types/api'
 
 export interface LoginAudit {
   id: number
@@ -39,7 +39,7 @@ const mockOpsAudits: OpsAudit[] = [
 
 export const auditApi = {
   // 获取登录审计
-  getLoginAudit(params?: any): Promise<any> {
+  getLoginAudit(_params?: any): Promise<ApiResponse<PaginatedData<LoginAudit>>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({
@@ -55,7 +55,7 @@ export const auditApi = {
   },
 
   // 获取运维操作审计
-  getOpsAudit(params?: any): Promise<any> {
+  getOpsAudit(_params?: any): Promise<ApiResponse<PaginatedData<OpsAudit>>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({
diff --git a/frontend/src/api/auth.ts b/frontend/src/api/auth.ts
index 06681fd..cff3e17 100644
--- a/frontend/src/api/auth.ts
+++ b/frontend/src/api/auth.ts
@@ -1,4 +1,4 @@
-import request from './request'
+import type { ApiResponse } from '@/types/api'
 
 export interface LoginRequest {
   username: string
@@ -30,7 +30,7 @@ const mockUser: UserInfo = {
 
 export const authApi = {
   // 登录
-  login(data: LoginRequest): Promise<any> {
+  login(_data: LoginRequest): Promise<ApiResponse<LoginResponse>> {
     // MVP 阶段使用 Mock 数据
     return new Promise((resolve) => {
       setTimeout(() => {
@@ -48,16 +48,16 @@ export const authApi = {
   },
 
   // 登出
-  logout(): Promise<any> {
+  logout(): Promise<ApiResponse<null>> {
     return new Promise((resolve) => {
       setTimeout(() => {
-        resolve({ code: 0, message: 'success' })
+        resolve({ code: 0, message: 'success', data: null })
       }, 200)
     })
   },
 
   // 获取用户信息
-  getUserInfo(): Promise<any> {
+  getUserInfo(): Promise<ApiResponse<UserInfo>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({
diff --git a/frontend/src/api/request.ts b/frontend/src/api/request.ts
index 295a2a4..3931f94 100644
--- a/frontend/src/api/request.ts
+++ b/frontend/src/api/request.ts
@@ -1,6 +1,8 @@
-import axios from 'axios'
+import axios, { type AxiosResponse, type AxiosError } from 'axios'
 import { getToken, removeToken } from '@/utils/auth'
 import { ElMessage } from 'element-plus'
+import type { ApiResponse } from '@/types/api'
+import { codeMessageMap } from '@/types/api'
 
 const request = axios.create({
   baseURL: '/api/v1',
@@ -21,22 +23,55 @@ request.interceptors.request.use(
   }
 )
 
+/** HTTP 状态码对应的用户友好提示 */
+const httpMessageMap: Record<number, string> = {
+  400: '请求参数错误',
+  401: '未授权，请重新登录',
+  403: '没有权限执行此操作',
+  404: '请求的资源不存在',
+  408: '请求超时，请稍后重试',
+  500: '服务器内部错误',
+  502: '网关错误',
+  503: '服务暂时不可用，请稍后重试',
+}
+
+/** 根据后端错误码获取用户友好提示 */
+function getBusinessMessage(code: number, fallback?: string): string {
+  return codeMessageMap[code] || fallback || '请求失败'
+}
+
 // 响应拦截器
 request.interceptors.response.use(
-  (response) => {
+  (response: AxiosResponse<ApiResponse>) => {
     const { data } = response
     if (data.code !== 0) {
-      ElMessage.error(data.message || '请求失败')
-      return Promise.reject(new Error(data.message))
+      const message = getBusinessMessage(data.code, data.message)
+      ElMessage.error(message)
+      return Promise.reject(new Error(message))
     }
-    return data
+    return data as any
   },
-  (error) => {
-    if (error.response?.status === 401) {
-      removeToken()
-      window.location.href = '/login'
+  (error: AxiosError<ApiResponse>) => {
+    // 优先使用后端返回的错误信息
+    const backendMessage = error.response?.data?.message
+
+    if (error.response) {
+      const status = error.response.status
+
+      if (status === 401) {
+        removeToken()
+        window.location.href = '/login'
+        ElMessage.error(backendMessage || '未授权，请重新登录')
+      } else {
+        const message = backendMessage || httpMessageMap[status] || `请求失败 (${status})`
+        ElMessage.error(message)
+      }
+    } else if (error.code === 'ECONNABORTED') {
+      ElMessage.error('请求超时，请检查网络后重试')
+    } else {
+      ElMessage.error('网络连接异常，请检查网络')
     }
-    ElMessage.error(error.message || '网络错误')
+
     return Promise.reject(error)
   }
 )
diff --git a/frontend/src/api/subsystem.ts b/frontend/src/api/subsystem.ts
index a2771e0..d7338b9 100644
--- a/frontend/src/api/subsystem.ts
+++ b/frontend/src/api/subsystem.ts
@@ -1,4 +1,4 @@
-import request from './request'
+import type { ApiResponse } from '@/types/api'
 
 export interface Subsystem {
   id: number
@@ -10,6 +10,11 @@ export interface Subsystem {
   sso_enabled: boolean
 }
 
+export interface SSOResponse {
+  sso_url: string
+  expires_in: number
+}
+
 // Mock 数据
 const mockSubsystems: Subsystem[] = [
   {
@@ -70,7 +75,7 @@ const mockSubsystems: Subsystem[] = [
 
 export const subsystemApi = {
   // 获取子系统列表
-  getSubsystems(): Promise<any> {
+  getSubsystems(): Promise<ApiResponse<Subsystem[]>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({
@@ -83,7 +88,7 @@ export const subsystemApi = {
   },
 
   // 获取 SSO 跳转 URL
-  getSSOUrl(id: number): Promise<any> {
+  getSSOUrl(id: number): Promise<ApiResponse<SSOResponse>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         const subsystem = mockSubsystems.find((s) => s.id === id)
diff --git a/frontend/src/router/index.ts b/frontend/src/router/index.ts
index 4e30cac..8ece879 100644
--- a/frontend/src/router/index.ts
+++ b/frontend/src/router/index.ts
@@ -97,7 +97,7 @@ const router = createRouter({
 })
 
 // 路由守卫
-router.beforeEach((to, from, next) => {
+router.beforeEach((to, _from, next) => {
   const token = getToken()
 
   if (to.meta.requiresAuth !== false && !token) {
diff --git a/frontend/src/types/api.ts b/frontend/src/types/api.ts
new file mode 100644
index 0000000..3ff1886
--- /dev/null
+++ b/frontend/src/types/api.ts
@@ -0,0 +1,53 @@
+/**
+ * 后端统一响应格式类型定义
+ * 对应 server/internal/handler/response.go
+ */
+
+/** 统一 JSON 响应信封 */
+export interface ApiResponse<T = any> {
+  /** 业务状态码，0 表示成功 */
+  code: number
+  /** 提示信息 */
+  message: string
+  /** 响应数据 */
+  data: T
+  /** 参数校验错误详情（可选） */
+  details?: Record<string, string[]>
+}
+
+/** 分页数据结构 */
+export interface PaginatedData<T> {
+  total: number
+  items: T[]
+}
+
+/** 业务错误码常量，与后端一一对应 */
+export const ApiCode = {
+  /** 成功 */
+  SUCCESS: 0,
+  /** LDAP 认证失败 */
+  LDAP_AUTH_FAILED: 10001,
+  /** 用户名或密码错误 */
+  INVALID_CREDENTIALS: 10002,
+  /** Token 已过期 */
+  TOKEN_EXPIRED: 10003,
+  /** SSO 未配置 */
+  SSO_NOT_CONFIGURED: 10004,
+  /** SSO 跳转地址生成失败 */
+  SSO_GENERATE_FAILED: 10005,
+  /** 任务创建失败 */
+  TASK_CREATE_FAILED: 20001,
+  /** 任务执行超时 */
+  TASK_EXEC_TIMEOUT: 20002,
+} as const
+
+/** 错误码到用户友好提示的映射 */
+export const codeMessageMap: Record<number, string> = {
+  [ApiCode.LDAP_AUTH_FAILED]: 'LDAP 认证服务异常，请稍后重试',
+  [ApiCode.INVALID_CREDENTIALS]: '用户名或密码错误',
+  [ApiCode.TOKEN_EXPIRED]: '登录已过期，请重新登录',
+  [ApiCode.SSO_NOT_CONFIGURED]: '该子系统未配置 SSO，请联系管理员',
+  [ApiCode.SSO_GENERATE_FAILED]: '生成 SSO 跳转链接失败，请稍后重试',
+  [ApiCode.TASK_CREATE_FAILED]: '创建任务失败，请检查参数后重试',
+  [ApiCode.TASK_EXEC_TIMEOUT]: '任务执行超时，请稍后查看结果',
+}
diff --git a/frontend/src/views/audit/LoginAudit.vue b/frontend/src/views/audit/LoginAudit.vue
index c3540ed..46465bf 100644
--- a/frontend/src/views/audit/LoginAudit.vue
+++ b/frontend/src/views/audit/LoginAudit.vue
@@ -33,9 +33,13 @@ const auditData = ref<LoginAudit[]>([])
 const total = ref(0)
 
 const fetchData = async () => {
-  const { data } = await auditApi.getLoginAudit()
-  auditData.value = data.items
-  total.value = data.total
+  try {
+    const { data } = await auditApi.getLoginAudit()
+    auditData.value = data.items
+    total.value = data.total
+  } catch {
+    // 错误已由 request 拦截器统一处理
+  }
 }
 
 const refresh = () => {
diff --git a/frontend/src/views/audit/OpsAudit.vue b/frontend/src/views/audit/OpsAudit.vue
index 7eb2567..e79875b 100644
--- a/frontend/src/views/audit/OpsAudit.vue
+++ b/frontend/src/views/audit/OpsAudit.vue
@@ -34,9 +34,13 @@ const auditData = ref<OpsAudit[]>([])
 const total = ref(0)
 
 const fetchData = async () => {
-  const { data } = await auditApi.getOpsAudit()
-  auditData.value = data.items
-  total.value = data.total
+  try {
+    const { data } = await auditApi.getOpsAudit()
+    auditData.value = data.items
+    total.value = data.total
+  } catch {
+    // 错误已由 request 拦截器统一处理
+  }
 }
 
 const refresh = () => {
diff --git a/frontend/src/views/auth/Login.vue b/frontend/src/views/auth/Login.vue
index ebba93f..db9f04a 100644
--- a/frontend/src/views/auth/Login.vue
+++ b/frontend/src/views/auth/Login.vue
@@ -84,8 +84,8 @@ const handleLogin = async () => {
     await login(form.username, form.password)
     ElMessage.success('登录成功')
     router.push('/')
-  } catch (error: any) {
-    ElMessage.error(error.message || '登录失败')
+  } catch {
+    // 错误已由 request 拦截器统一处理
   } finally {
     loading.value = false
   }
diff --git a/frontend/src/views/subsystem/Navigation.vue b/frontend/src/views/subsystem/Navigation.vue
index 2effdd9..44a50f7 100644
--- a/frontend/src/views/subsystem/Navigation.vue
+++ b/frontend/src/views/subsystem/Navigation.vue
@@ -24,8 +24,12 @@ import SubsystemCard from '@/components/SubsystemCard.vue'
 const subsystems = ref<Subsystem[]>([])
 
 onMounted(async () => {
-  const { data } = await subsystemApi.getSubsystems()
-  subsystems.value = data
+  try {
+    const { data } = await subsystemApi.getSubsystems()
+    subsystems.value = data
+  } catch {
+    // 错误已由 request 拦截器统一处理
+  }
 })
 </script>