diff --git a/apps/web/e2e/test_auth.spec.ts b/apps/web/e2e/test_auth.spec.ts
index cb34b90fa..121600034 100755
--- a/apps/web/e2e/test_auth.spec.ts
+++ b/apps/web/e2e/test_auth.spec.ts
@@ -150,6 +150,36 @@ test.describe("认证流程", () => {
     expect([400, 422]).toContain(response.status());
   });
 
+  test("注册用户名为空 - 反向", async ({ request }) => {
+    const response = await request.post(`${apiBase}/auth/register`, {
+      data: {
+        email: uniqueEmail("emptyuser"),
+        password: PASSWORD,
+        username: "",
+        display_name: "Empty Username",
+      },
+    });
+
+    expect([400, 422], "用户名为空应返回 4xx 校验错误").toContain(
+      response.status(),
+    );
+  });
+
+  test("注册缺用户名字段 - 反向", async ({ request }) => {
+    const response = await request.post(`${apiBase}/auth/register`, {
+      data: {
+        email: uniqueEmail("nouser"),
+        password: PASSWORD,
+        display_name: "No Username Field",
+      },
+    });
+
+    expect(
+      [400, 422],
+      "缺少用户名字段应返回 4xx 校验错误",
+    ).toContain(response.status());
+  });
+
   // ─── 登录 ────────────────────────────────────────────
 
   test("登录成功 - 正向", async ({ request }) => {