diff --git a/.env.development b/.env.development
index e833169..3ecb58e 100644
--- a/.env.development
+++ b/.env.development
@@ -1,2 +1,3 @@
-# 已切换为真实后端接口
-VITE_USE_MOCK=false
+# 后端服务地址（开发环境）
+# 头像等静态资源通过此地址访问，生产环境留空即使用相对路径
+VITE_BACKEND_URL=http://localhost:8080
diff --git a/src/components/baseLayouts/EditProfileDialog.vue b/src/components/baseLayouts/EditProfileDialog.vue
index b07543d..3d67946 100644
--- a/src/components/baseLayouts/EditProfileDialog.vue
+++ b/src/components/baseLayouts/EditProfileDialog.vue
@@ -239,6 +239,7 @@ import {
 } from '@element-plus/icons-vue'
 import { useAccountStore } from '@/stores'
 import { storeToRefs } from 'pinia'
+import { getAvatarUrl } from '@/utils'
 import AvatarCropper from './AvatarCropper.vue'
 
 /** 编辑资料表单数据 */
@@ -306,11 +307,11 @@ const hasAvatar = computed(() => {
   return !!(av && av.length > 0)
 })
 
-/** 头像显示源：裁剪预览 > 移除状态 > store 数据 */
+/** 头像显示源：裁剪预览 > 移除状态 > store 数据（已拼接后端域名） */
 const avatarDisplaySrc = computed(() => {
   if (avatarRemoved.value) return ''
   if (croppedPreviewUrl.value) return croppedPreviewUrl.value
-  return accountInfo.value?.avatar || ''
+  return getAvatarUrl(accountInfo.value?.avatar)
 })
 
 /** 根据生日计算年龄（周岁） */
diff --git a/src/components/baseLayouts/TableCard.vue b/src/components/baseLayouts/TableCard.vue
index 27a4fa8..c46d0d2 100644
--- a/src/components/baseLayouts/TableCard.vue
+++ b/src/components/baseLayouts/TableCard.vue
@@ -30,7 +30,7 @@
         >
           <div class="table-card__chair-seat">
             <img
-              :src="room.players[idx].avatar"
+              :src="getAvatarUrl(room.players[idx].avatar)"
               :alt="room.players[idx].nickname"
               class="table-card__chair-avatar"
             />
@@ -73,6 +73,7 @@
 <script setup lang="ts">
 import { computed } from 'vue'
 import type { RoomItem, RoomPlayer, RoomStatus } from '@/api/modules/game'
+import { getAvatarUrl } from '@/utils'
 
 const props = defineProps<{
   room: RoomItem
diff --git a/src/components/baseLayouts/UserBar.vue b/src/components/baseLayouts/UserBar.vue
index ee635e3..f06f570 100644
--- a/src/components/baseLayouts/UserBar.vue
+++ b/src/components/baseLayouts/UserBar.vue
@@ -138,6 +138,7 @@ import { ElMessage } from 'element-plus'
 import { Setting, EditPen, ArrowRight, Check, DocumentCopy, SwitchButton } from '@element-plus/icons-vue'
 import { useAccountStore } from '@/stores'
 import { UserStatus, type UserStatusType } from '@/api/modules/user'
+import { getAvatarUrl } from '@/utils'
 import EditProfileDialog from './EditProfileDialog.vue'
 
 /** 在线状态选项 */
@@ -170,7 +171,7 @@ const currentStatus = computed<StatusOption>(() => {
   return backendStatus ? (statusMap.get(backendStatus) ?? STATUS_OPTIONS[0]!) : STATUS_OPTIONS[0]!
 })
 
-const userAvatar = computed(() => accountInfo.value?.avatar || '')
+const userAvatar = computed(() => getAvatarUrl(accountInfo.value?.avatar))
 const displayName = computed(() => accountInfo.value?.nickName || '未登录')
 const signatureText = computed(() => accountInfo.value?.signature || '这个人很懒，什么都没写...')
 
diff --git a/src/utils/avatar.ts b/src/utils/avatar.ts
new file mode 100644
index 0000000..9ce73bb
--- /dev/null
+++ b/src/utils/avatar.ts
@@ -0,0 +1,33 @@
+/**
+ * 头像 URL 工具
+ *
+ * 将后端返回的相对头像路径拼接为完整可访问的 URL。
+ * 开发环境使用 VITE_BACKEND_URL（如 http://localhost:8080），
+ * 生产环境使用相对路径（前后端同域）。
+ */
+
+/** 后端基础 URL（Vite 环境变量，开发时为 http://localhost:8080，生产为空） */
+const BACKEND_BASE = import.meta.env.VITE_BACKEND_URL || ''
+
+/**
+ * 获取完整的头像展示 URL
+ *
+ * - 空值/undefined 返回空字符串，前端显示默认头像
+ * - data URI（注册默认头像）直接返回
+ * - 已是完整 URL（http/https 开头）直接返回
+ * - 相对路径（如上传的自定义头像）拼接后端域名
+ *
+ * @param avatarPath - 后端返回的头像路径，如 "/uploads/avatars/xxx.jpg" 或 "data:image/svg+xml;base64,..."
+ * @returns 可直接用于 <img src> 的完整 URL
+ */
+export function getAvatarUrl(avatarPath: string | null | undefined): string {
+  if (!avatarPath) return ''
+
+  // data URI 或完整 URL，直接返回
+  if (avatarPath.startsWith('data:') || avatarPath.startsWith('http://') || avatarPath.startsWith('https://')) {
+    return avatarPath
+  }
+
+  // 相对路径拼接后端域名
+  return BACKEND_BASE + avatarPath
+}
diff --git a/src/utils/index.ts b/src/utils/index.ts
index ba241ff..157b4df 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -1,2 +1,3 @@
 export * from './eventBus.ts'
 export * from './useDebouncedRef.ts'
+export * from './avatar.ts'