diff --git a/backend/src/main/java/com/stdproject/entity/LoginUser.java b/backend/src/main/java/com/stdproject/entity/LoginUser.java
index c1ff2bb..2d9f73b 100644
--- a/backend/src/main/java/com/stdproject/entity/LoginUser.java
+++ b/backend/src/main/java/com/stdproject/entity/LoginUser.java
@@ -11,6 +11,7 @@ import org.springframework.security.core.userdetails.UserDetails;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 @Data
 @NoArgsConstructor
@@ -19,9 +20,9 @@ public class LoginUser implements UserDetails {
 
     private User user;
 
-    private List<Map> permissions;
+    private Set<Map> permissions;
 
-    public LoginUser(User user, List<Map> permissions) {
+    public LoginUser(User user, Set<Map> permissions) {
         this.user = user;
         this.permissions = permissions;
     }
@@ -29,7 +30,7 @@ public class LoginUser implements UserDetails {
     @JSONField(serialize = false)
     private List<SimpleGrantedAuthority> authorities;
 
-    public List<Map>  getPermissions() {
+    public Set<Map>  getPermissions() {
         return permissions;
     }
 
diff --git a/backend/src/main/java/com/stdproject/service/CustomUserDetailsService.java b/backend/src/main/java/com/stdproject/service/CustomUserDetailsService.java
index ab26b02..ae3d239 100644
--- a/backend/src/main/java/com/stdproject/service/CustomUserDetailsService.java
+++ b/backend/src/main/java/com/stdproject/service/CustomUserDetailsService.java
@@ -48,7 +48,7 @@ public class CustomUserDetailsService implements UserDetailsService {
         if (appUser == null) {
             throw new UsernameNotFoundException("用户不存在: " + username);
         }
-        List<Map> permissions = buildUserAuthorities(appUser);
+        Set<Map> permissions = buildUserAuthorities(appUser);
         LoginUser loginUser = new LoginUser(appUser,permissions);
         return loginUser;
 
@@ -60,8 +60,8 @@ public class CustomUserDetailsService implements UserDetailsService {
      * @param appUser 用户信息
      * @return 权限集合
      */
-    private List<Map> buildUserAuthorities(User appUser) {
-        List<Map> permissions = new ArrayList<>();
+    private Set<Map> buildUserAuthorities(User appUser) {
+        Set<Map> permissions = new HashSet<>();
         
         try {
             // 使用RoleMapper直接查询用户的角色信息