diff --git a/backend/src/VendingMachine.Domain/Entities/User.cs b/backend/src/VendingMachine.Domain/Entities/User.cs
index b4343f79..f6948c52 100644
--- a/backend/src/VendingMachine.Domain/Entities/User.cs
+++ b/backend/src/VendingMachine.Domain/Entities/User.cs
@@ -2,7 +2,17 @@ namespace VendingMachine.Domain.Entities;
 
 public class User
 {
-    public string Uid { get; set; } = Guid.NewGuid().ToString("N")[..12];
+    private static readonly Random _random = new();
+
+    public string Uid { get; set; } = GenerateUid();
+
+    /// <summary>
+    /// 生成6位随机数字UID，不以0开头（100000-999999）
+    /// </summary>
+    public static string GenerateUid()
+    {
+        return _random.Next(100000, 999999).ToString();
+    }
     public string Phone { get; set; } = string.Empty;
     public string AreaCode { get; set; } = string.Empty;
     public string Nickname { get; set; } = string.Empty;
diff --git a/backend/src/VendingMachine.Infrastructure/Services/UserService.cs b/backend/src/VendingMachine.Infrastructure/Services/UserService.cs
index f68db9c3..69debdb2 100644
--- a/backend/src/VendingMachine.Infrastructure/Services/UserService.cs
+++ b/backend/src/VendingMachine.Infrastructure/Services/UserService.cs
@@ -92,8 +92,16 @@ public class UserService : IUserService
 
         if (user == null)
         {
+            // 生成唯一的6位UID
+            string uid;
+            do
+            {
+                uid = User.GenerateUid();
+            } while (await _db.Users.IgnoreQueryFilters().AnyAsync(u => u.Uid == uid));
+
             user = new User
             {
+                Uid = uid,
                 Phone = request.Phone,
                 AreaCode = request.AreaCode,
                 Nickname = IUserService.GenerateDefaultNickname()
diff --git a/mobile/pages/login/login.vue b/mobile/pages/login/login.vue
index 902e6e02..bfcb2cfc 100644
--- a/mobile/pages/login/login.vue
+++ b/mobile/pages/login/login.vue
@@ -1,7 +1,7 @@
 <template>
 	<view class="login-page">
 		<!-- 全屏背景图 -->
-		<image class="bg-image" src="/static/login_bg.png" mode="aspectFill" />
+		<image class="bg-image" src="/static/logo_bg.png" mode="aspectFill" />
 
 		<!-- 自定义导航栏 -->
 		<view class="custom-nav" :style="{ paddingTop: statusBarHeight + 'px' }">
diff --git a/mobile/static/logo_bg.png b/mobile/static/logo_bg.png
new file mode 100644
index 00000000..e71fe5e6
Binary files /dev/null and b/mobile/static/logo_bg.png differ