diff --git a/backend/src/main/java/com/xly/erp/module/usr/mapper/UserPermissionMapper.java b/backend/src/main/java/com/xly/erp/module/usr/mapper/UserPermissionMapper.java
index c1741ae..81f765e 100644
--- a/backend/src/main/java/com/xly/erp/module/usr/mapper/UserPermissionMapper.java
+++ b/backend/src/main/java/com/xly/erp/module/usr/mapper/UserPermissionMapper.java
@@ -2,6 +2,11 @@ package com.xly.erp.module.usr.mapper;
 
 import com.baomidou.mybatisplus.core.mapper.BaseMapper;
 import com.xly.erp.module.usr.entity.UserPermission;
+import org.apache.ibatis.annotations.Delete;
+import org.apache.ibatis.annotations.Param;
 
 public interface UserPermissionMapper extends BaseMapper<UserPermission> {
+
+    @Delete("DELETE FROM tUserPermission WHERE iUserId = #{userId}")
+    int deleteByUserId(@Param("userId") Integer userId);
 }
diff --git a/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java b/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java
index 435ede2..b40b961 100644
--- a/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java
+++ b/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java
@@ -93,6 +93,49 @@ class UserMapperIT {
         assertThat(count).isEqualTo(1);
     }
 
+    @Test
+    void userPermissionMapper_deleteByUserId_removesAllRowsForGivenUser() {
+        User user1 = newUser("sp_test_del_u1", "用户1");
+        userMapper.insert(user1);
+        User user2 = newUser("sp_test_del_u2", "用户2");
+        userMapper.insert(user2);
+
+        jdbcTemplate.update(
+                "INSERT INTO tPermissionCategory (sBrandsId, sSubsidiaryId, tCreateDate, sCategoryCode, sCategoryName, "
+                        + "iSortOrder, sCreatedBy, bDeleted) VALUES "
+                        + "('XLY','XLY', NOW(), 'sp_test_del_c1', '权限C1', 0, 'STUB', 0),"
+                        + "('XLY','XLY', NOW(), 'sp_test_del_c2', '权限C2', 0, 'STUB', 0)");
+        Integer cat1 = jdbcTemplate.queryForObject(
+                "SELECT iIncrement FROM tPermissionCategory WHERE sCategoryCode = 'sp_test_del_c1'", Integer.class);
+        Integer cat2 = jdbcTemplate.queryForObject(
+                "SELECT iIncrement FROM tPermissionCategory WHERE sCategoryCode = 'sp_test_del_c2'", Integer.class);
+
+        insertUserPermission(user1.getIIncrement(), cat1);
+        insertUserPermission(user1.getIIncrement(), cat2);
+        insertUserPermission(user2.getIIncrement(), cat1);
+
+        int affected = userPermissionMapper.deleteByUserId(user1.getIIncrement());
+        assertThat(affected).isEqualTo(2);
+
+        Integer u1Count = jdbcTemplate.queryForObject(
+                "SELECT COUNT(1) FROM tUserPermission WHERE iUserId = ?", Integer.class, user1.getIIncrement());
+        Integer u2Count = jdbcTemplate.queryForObject(
+                "SELECT COUNT(1) FROM tUserPermission WHERE iUserId = ?", Integer.class, user2.getIIncrement());
+        assertThat(u1Count).isZero();
+        assertThat(u2Count).isEqualTo(1);
+    }
+
+    private void insertUserPermission(Integer userId, Integer catId) {
+        UserPermission rel = new UserPermission();
+        rel.setSBrandsId("XLY");
+        rel.setSSubsidiaryId("XLY");
+        rel.setTCreateDate(LocalDateTime.now());
+        rel.setIUserId(userId);
+        rel.setICategoryId(catId);
+        rel.setSCreatedBy("STUB_ADMIN");
+        userPermissionMapper.insert(rel);
+    }
+
     private User newUser(String userNo, String userName) {
         User u = new User();
         u.setSBrandsId("XLY");