diff --git a/module/story/test/lib/story.unittest.class.php b/module/story/test/lib/story.unittest.class.php
index 4711e8691e..27634a186b 100644
--- a/module/story/test/lib/story.unittest.class.php
+++ b/module/story/test/lib/story.unittest.class.php
@@ -1482,4 +1482,19 @@ class storyTest
 
         return $result;
     }
+
+    /**
+     * Test getDefaultShowGrades method.
+     *
+     * @param  array $gradeMenu
+     * @access public
+     * @return string
+     */
+    public function getDefaultShowGradesTest(array $gradeMenu): string
+    {
+        $result = $this->objectModel->getDefaultShowGrades($gradeMenu);
+        if(dao::isError()) return dao::getError();
+
+        return $result;
+    }
 }
diff --git a/module/story/test/model/getdefaultshowgrades.php b/module/story/test/model/getdefaultshowgrades.php
new file mode 100755
index 0000000000..9d48ef08bf
--- /dev/null
+++ b/module/story/test/model/getdefaultshowgrades.php
@@ -0,0 +1,66 @@
+#!/usr/bin/env php
+<?php
+
+/**
+
+title=测试 storyModel::getDefaultShowGrades();
+timeout=0
+cid=0
+
+- 步骤3：边界值测试空数组 @
+
+*/
+
+// 1. 导入依赖（路径固定，不可修改）
+include dirname(__FILE__, 5) . '/test/lib/init.php';
+include dirname(__FILE__, 2) . '/lib/story.unittest.class.php';
+
+// 3. 用户登录（选择合适角色）
+su('admin');
+
+// 4. 创建测试实例（变量名与模块名一致）
+$storyTest = new storyTest();
+
+// 5. 🔴 强制要求：必须包含至少5个测试步骤
+r($storyTest->getDefaultShowGradesTest(array(
+    array('items' => array(
+        array('value' => '1'),
+        array('value' => '2')
+    ))
+))) && p() && e('1,2,'); // 步骤1：正常情况测试单级菜单
+
+r($storyTest->getDefaultShowGradesTest(array(
+    array('items' => array(
+        array('value' => 'story'),
+        array('value' => 'requirement')
+    )),
+    array('items' => array(
+        array('value' => 'epic'),
+        array('value' => 'feature')
+    ))
+))) && p() && e('story,requirement,epic,feature,'); // 步骤2：正常情况测试多级菜单
+
+r($storyTest->getDefaultShowGradesTest(array())) && p() && e(''); // 步骤3：边界值测试空数组
+
+r($storyTest->getDefaultShowGradesTest(array(
+    array('items' => array(
+        array('value' => 1),
+        array('value' => 2),
+        array('value' => 3)
+    ))
+))) && p() && e('1,2,3,'); // 步骤4：测试包含数字值的菜单
+
+r($storyTest->getDefaultShowGradesTest(array(
+    array('items' => array(
+        array('value' => 'level1_item1'),
+        array('value' => 'level1_item2')
+    )),
+    array('items' => array(
+        array('value' => 'level2_item1'),
+        array('value' => 'level2_item2'),
+        array('value' => 'level2_item3')
+    )),
+    array('items' => array(
+        array('value' => 'level3_item1')
+    ))
+))) && p() && e('level1_item1,level1_item2,level2_item1,level2_item2,level2_item3,level3_item1,'); // 步骤5：测试复杂多级嵌套菜单
\ No newline at end of file