diff --git a/admin-server/gateway.go b/admin-server/gateway.go
index 497c550..faa2b45 100644
--- a/admin-server/gateway.go
+++ b/admin-server/gateway.go
@@ -191,13 +191,20 @@ func writeListeners(b *strings.Builder, cfg *GatewayConfig, defaultServer bool)
 
 func writeErrorPages(b *strings.Builder, include404 bool) {
 	b.WriteString("    root /app/portal;\n")
+	// 关键：错误页与它自己的静态资源必须 `auth_request off`。
+	// 上游故障时 nginx 会内部跳转到 /500.html，而服务端的 auth_request 会被
+	// 这个内部请求继承 —— 于是"上游 502"最终以 401（认证失败）呈现给用户，
+	// 自定义错误页永远显示不出来。本轮实测踩到（日志里能看到 connect() refused，
+	// 客户端却收到 nginx 的默认 401 页）。
 	if include404 {
-		b.WriteString("    error_page 404 /404.html;\n    location = /404.html { internal; }\n")
+		b.WriteString("    error_page 404 /404.html;\n")
+		b.WriteString("    location = /404.html { internal; auth_request off; }\n")
 	}
-	b.WriteString("    error_page 500 502 503 504 /500.html;\n    location = /500.html { internal; }\n")
-	b.WriteString("    location ^~ /css/ { try_files $uri =404; }\n")
-	b.WriteString("    location = /favicon.svg { try_files $uri =404; }\n")
-	b.WriteString("    location = /favicon.ico { try_files $uri =404; }\n")
+	b.WriteString("    error_page 500 502 503 504 /500.html;\n")
+	b.WriteString("    location = /500.html { internal; auth_request off; }\n")
+	b.WriteString("    location ^~ /css/ { auth_request off; try_files $uri =404; }\n")
+	b.WriteString("    location = /favicon.svg { auth_request off; try_files $uri =404; }\n")
+	b.WriteString("    location = /favicon.ico { auth_request off; try_files $uri =404; }\n")
 }
 
 func writeProxyLocation(b *strings.Builder, r Route, path string, authOff bool) {
diff --git a/admin-server/gateway_test.go b/admin-server/gateway_test.go
index 8757f04..bda8d70 100644
--- a/admin-server/gateway_test.go
+++ b/admin-server/gateway_test.go
@@ -40,8 +40,13 @@ func TestRenderGatewayConfAuthPerRoute(t *testing.T) {
 	if open == "" {
 		t.Fatalf("缺少开放域名的 server 块")
 	}
-	if contains(open, "auth_request") {
-		t.Fatalf("未受保护的域名不应有 auth_request:\n%s", open)
+	// 断言的是"强制闸门" auth_request /_auth;，不是裸字符串：
+	// 错误页会合法地带 auth_request off;，用裸字符串会把正确配置判成错误。
+	if contains(open, "auth_request /_auth;") {
+		t.Fatalf("未受保护的域名不应有强制认证闸门:\n%s", open)
+	}
+	if !contains(open, "auth_request off;") {
+		t.Fatalf("错误页应显式关闭认证:\n%s", open)
 	}
 	// 兜底 server：未知域名必须被拒绝，而不是落进某条路由
 	if !contains(out, "default_server") || !contains(out, "return 404") {
@@ -335,3 +340,21 @@ func TestRenderGatewayConfTLSHttp2Compatible(t *testing.T) {
 		t.Fatalf("证书路径未写入")
 	}
 }
+
+// 错误页必须 auth_request off：否则上游故障会以 401 呈现，自定义错误页永远看不到。
+func TestRenderGatewayConfErrorPagesSkipAuth(t *testing.T) {
+	out, err := RenderGatewayConf(&GatewayConfig{ListenPort: 8081, AuthURL: "http://x/_auth",
+		LoginURL: "https://l/login", Routes: []Route{{Host: "a.com", Upstream: "http://a", RequireLogin: true}}})
+	if err != nil {
+		t.Fatalf("渲染失败: %v", err)
+	}
+	for _, want := range []string{
+		"location = /500.html { internal; auth_request off; }",
+		"location = /404.html { internal; auth_request off; }",
+		"location ^~ /css/ { auth_request off;",
+	} {
+		if !contains(out, want) {
+			t.Fatalf("错误页缺少 auth_request off（%q）:\n%s", want, out)
+		}
+	}
+}