diff --git a/backend-java/src/test/java/com/nanri/aiimage/modules/permission/service/support/Task142Test.java b/backend-java/src/test/java/com/nanri/aiimage/modules/permission/service/support/Task142Test.java
new file mode 100644
index 00000000..f59b86f7
--- /dev/null
+++ b/backend-java/src/test/java/com/nanri/aiimage/modules/permission/service/support/Task142Test.java
@@ -0,0 +1,67 @@
+package com.nanri.aiimage.modules.permission.service.support;
+
+import com.nanri.aiimage.modules.permission.model.vo.PermissionMenuItemVo;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/** task-142：menu_type=admin 过滤规则。 */
+class Task142Test {
+
+    private PermissionMenuItemVo item(Long id, String key, String type) {
+        PermissionMenuItemVo vo = new PermissionMenuItemVo();
+        vo.setId(id);
+        vo.setColumnKey(key);
+        vo.setMenuType(type);
+        return vo;
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_normal_primary_path() {
+        List<PermissionMenuItemVo> admin = AdminMenuTreeBuilder.filterByMenuType(
+                List.of(item(1L, "a", "admin"), item(2L, "b", "client")), "admin");
+        assertEquals(1, admin.size());
+        assertEquals("a", admin.get(0).getColumnKey());
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_normal_variant_input() {
+        assertTrue(AdminMenuTreeBuilder.filterByMenuType(List.of(item(1L, "x", "client")), "admin").isEmpty());
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_repeated_is_idempotent() {
+        List<PermissionMenuItemVo> menus = List.of(item(1L, "a", "admin"));
+        assertEquals(AdminMenuTreeBuilder.filterByMenuType(menus, "admin"),
+                AdminMenuTreeBuilder.filterByMenuType(menus, "admin"));
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_boundary_empty_input() {
+        assertTrue(AdminMenuTreeBuilder.filterByMenuType(null, "admin").isEmpty());
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_boundary_single_item() {
+        assertEquals(1, AdminMenuTreeBuilder.filterByMenuType(List.of(item(3L, "a", "admin")), "admin").size());
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_boundary_limit_or_missing_field() {
+        assertEquals(0, AdminMenuTreeBuilder.filterByMenuType(List.of(item(1L, "a", null)), "admin").size());
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_invalid_input_rejected() {
+        assertEquals(0, AdminMenuTreeBuilder.filterByMenuType(List.of(item(1L, "a", "admin")), null).size());
+    }
+
+    @Test
+    void test_task_142_define_menu_typeadmin_dependency_failure_returns_actionable_message() {
+        // 保留 admin 域；普通用户经有效权限输入再过滤，Controller 不复算授权。
+        assertEquals("admin", AdminMenuTreeBuilder.filterByMenuType(List.of(item(1L, "a", "admin")), "admin").get(0).getMenuType());
+    }
+}