diff --git a/back/src/main/java/com/heeexy/example/dao/UserDao.java b/back/src/main/java/com/heeexy/example/dao/UserDao.java
index a68e7ca..f6a9bbe 100644
--- a/back/src/main/java/com/heeexy/example/dao/UserDao.java
+++ b/back/src/main/java/com/heeexy/example/dao/UserDao.java
@@ -35,6 +35,14 @@ public interface UserDao {
      */
     List<JSONObject> getAllRoles();
 
+    /**
+     * 校验用户名是否已存在
+     *
+     * @param jsonObject
+     * @return
+     */
+    int queryExistUsername(JSONObject jsonObject);
+
     /**
      * 新增用户
      *
@@ -50,6 +58,7 @@ public interface UserDao {
      * @return
      */
     int updateUser(JSONObject jsonObject);
+
     /**
      * 角色列表
      *
diff --git a/back/src/main/java/com/heeexy/example/service/impl/UserServiceImpl.java b/back/src/main/java/com/heeexy/example/service/impl/UserServiceImpl.java
index 9290247..41e1530 100644
--- a/back/src/main/java/com/heeexy/example/service/impl/UserServiceImpl.java
+++ b/back/src/main/java/com/heeexy/example/service/impl/UserServiceImpl.java
@@ -46,6 +46,10 @@ public class UserServiceImpl implements UserService {
      */
     @Override
     public JSONObject addUser(JSONObject jsonObject) {
+        int exist = userDao.queryExistUsername(jsonObject);
+        if (exist > 0) {
+            return CommonUtil.errorJson(ErrorEnum.E_10009);
+        }
         userDao.addUser(jsonObject);
         return CommonUtil.successJson();
     }
diff --git a/back/src/main/java/com/heeexy/example/util/constants/ErrorEnum.java b/back/src/main/java/com/heeexy/example/util/constants/ErrorEnum.java
index a06290f..e0e40e2 100644
--- a/back/src/main/java/com/heeexy/example/util/constants/ErrorEnum.java
+++ b/back/src/main/java/com/heeexy/example/util/constants/ErrorEnum.java
@@ -6,13 +6,14 @@ package com.heeexy.example.util.constants;
  */
 public enum ErrorEnum {
     /*
-    * 错误信息
-    * */
+     * 错误信息
+     * */
     E_400("400", "请求处理异常，请稍后再试"),
     E_500("500", "请求方式有误,请检查 GET/POST"),
     E_501("501", "请求路径不存在"),
     E_502("502", "权限不足"),
     E_10008("10008", "角色删除失败,尚有用户属于此角色"),
+    E_10009("10009", "账户已存在"),
 
     E_20011("20011", "登陆已过期,请重新登陆"),
 
diff --git a/back/src/main/resources/mapper/PermissionMapper.xml b/back/src/main/resources/mapper/PermissionMapper.xml
index 3bdb373..ec761ac 100644
--- a/back/src/main/resources/mapper/PermissionMapper.xml
+++ b/back/src/main/resources/mapper/PermissionMapper.xml
@@ -28,6 +28,7 @@
         LEFT JOIN sys_role_permission rp ON u.role_id = rp.role_id
         LEFT JOIN sys_permission p ON rp.permission_id = p.id
         WHERE u.username = #{username}
+        AND u.delete_status='1'
     </select>
 
     <select id="getAllPermission" resultType="String">
diff --git a/back/src/main/resources/mapper/UserMapper.xml b/back/src/main/resources/mapper/UserMapper.xml
index c8132c3..7d7f476 100644
--- a/back/src/main/resources/mapper/UserMapper.xml
+++ b/back/src/main/resources/mapper/UserMapper.xml
@@ -192,4 +192,10 @@
             role_name = #{roleName}
         WHERE id = #{roleId}
     </update>
+    <select id="queryExistUsername" resultType="int">
+        select count(0)
+         from sys_user
+         WHERE username=#{username}
+         AND delete_status='1';
+    </select>
 </mapper>
\ No newline at end of file