diff --git a/backend/src/main/java/com/designhub/service/UserService.java b/backend/src/main/java/com/designhub/service/UserService.java
index b17ef5b..629c788 100644
--- a/backend/src/main/java/com/designhub/service/UserService.java
+++ b/backend/src/main/java/com/designhub/service/UserService.java
@@ -6,6 +6,7 @@ import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.designhub.dto.LoginDTO;
 import com.designhub.dto.RegisterDTO;
 import com.designhub.entity.Department;
+import com.designhub.entity.Role;
 import com.designhub.entity.User;
 import com.designhub.entity.UserDepartment;
 import com.designhub.exception.BusinessException;
@@ -27,10 +28,13 @@ import org.springframework.util.StringUtils;
 
 import java.time.LocalDateTime;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import java.util.HashMap;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 /**
@@ -343,18 +347,17 @@ public class UserService {
             throw new BusinessException("用户不存在");
         }
 
-        // 将角色ID列表转换为逗号分隔的字符串
-        if (roleIds != null && !roleIds.isEmpty()) {
-            String roleIdsStr = roleIds.stream()
-                .map(String::valueOf)
-                .reduce((a, b) -> a + "," + b)
-                .orElse("");
-            user.setRoleIds(roleIdsStr);
-            userMapper.updateById(user);
-        } else {
-            user.setRoleIds(null);
-            userMapper.updateById(user);
-        }
+        Set<Long> targetRoleIds = roleIds == null ? Collections.emptySet() : new LinkedHashSet<>(roleIds);
+        String roleIdsStr = targetRoleIds.isEmpty()
+            ? null
+            : targetRoleIds.stream().map(String::valueOf).collect(Collectors.joining(","));
+        Integer targetIsAdmin = hasAdminRole(targetRoleIds) ? 1 : 0;
+
+        LambdaUpdateWrapper<User> updateWrapper = new LambdaUpdateWrapper<>();
+        updateWrapper.eq(User::getId, userId)
+            .set(User::getRoleIds, roleIdsStr)
+            .set(User::getIsAdmin, targetIsAdmin);
+        userMapper.update(null, updateWrapper);
 
         return true;
     }
@@ -1767,14 +1770,35 @@ public class UserService {
         if (user == null) {
             throw new BusinessException(ResultCode.NOT_FOUND, "用户不存在");
         }
-        
-        // 更新管理员标识
+
+        Set<Long> roleIdSet = parseRoleIds(user.getRoleIds());
+        boolean enableAdmin = isAdmin != null && isAdmin == 1;
+        if (enableAdmin) {
+            Long adminRoleId = findRoleIdByCode("ADMIN");
+            if (adminRoleId == null) {
+                throw new BusinessException(ResultCode.ERROR, "未找到管理员角色，请先检查角色配置");
+            }
+            roleIdSet.add(adminRoleId);
+        } else {
+            Long adminRoleId = findRoleIdByCode("ADMIN");
+            if (adminRoleId != null) {
+                roleIdSet.remove(adminRoleId);
+            }
+        }
+
+        String targetRoleIds = roleIdSet.isEmpty()
+            ? null
+            : roleIdSet.stream().map(String::valueOf).collect(Collectors.joining(","));
+        Integer targetIsAdmin = hasAdminRole(roleIdSet) ? 1 : 0;
+
         LambdaUpdateWrapper<User> updateWrapper = new LambdaUpdateWrapper<>();
-        updateWrapper.eq(User::getId, userId);
-        updateWrapper.set(User::getIsAdmin, isAdmin != null ? isAdmin : 0);
+        updateWrapper.eq(User::getId, userId)
+            .set(User::getRoleIds, targetRoleIds)
+            .set(User::getIsAdmin, targetIsAdmin);
         
         boolean result = userMapper.update(null, updateWrapper) > 0;
-        log.info("设置管理员身份结果: userId={}, isAdmin={}, result={}", userId, isAdmin, result);
+        log.info("设置管理员身份结果: userId={}, isAdmin={}, roleIds={}, result={}",
+            userId, targetIsAdmin, targetRoleIds, result);
         
         return result;
     }
@@ -1786,4 +1810,48 @@ public class UserService {
         User user = userMapper.selectById(userId);
         return user != null && user.getIsAdmin() != null && user.getIsAdmin() == 1;
     }
+
+    private Set<Long> parseRoleIds(String roleIdsStr) {
+        if (!StringUtils.hasText(roleIdsStr)) {
+            return new LinkedHashSet<>();
+        }
+        Set<Long> roleIds = new LinkedHashSet<>();
+        for (String part : roleIdsStr.split(",")) {
+            String trimmed = part == null ? "" : part.trim();
+            if (trimmed.isEmpty()) {
+                continue;
+            }
+            try {
+                roleIds.add(Long.parseLong(trimmed));
+            } catch (NumberFormatException ignored) {
+            }
+        }
+        return roleIds;
+    }
+
+    private Long findRoleIdByCode(String roleCode) {
+        if (!StringUtils.hasText(roleCode)) {
+            return null;
+        }
+        return roleService.getAllRoles().stream()
+            .filter(role -> roleCode.equalsIgnoreCase(role.getRoleCode()))
+            .map(Role::getId)
+            .findFirst()
+            .orElse(null);
+    }
+
+    private boolean hasAdminRole(Set<Long> roleIds) {
+        if (roleIds == null || roleIds.isEmpty()) {
+            return false;
+        }
+        Set<Long> adminRoleIds = roleService.getAllRoles().stream()
+            .filter(role -> "ADMIN".equalsIgnoreCase(role.getRoleCode())
+                || "SUPER_ADMIN".equalsIgnoreCase(role.getRoleCode()))
+            .map(Role::getId)
+            .collect(Collectors.toSet());
+        if (adminRoleIds.isEmpty()) {
+            return false;
+        }
+        return roleIds.stream().anyMatch(adminRoleIds::contains);
+    }
 }