diff --git a/app/api/payment/dulupay/create/route.ts b/app/api/payment/dulupay/create/route.ts
index 5dba9236b..8d6555506 100644
--- a/app/api/payment/dulupay/create/route.ts
+++ b/app/api/payment/dulupay/create/route.ts
@@ -29,6 +29,36 @@ function buildOutTradeNo() {
   return `DP${Date.now()}${random}`.slice(0, 64);
 }
 
+function normalizeBaseUrl(value?: string | null) {
+  const raw = String(value || "").trim();
+  if (!raw) return "";
+
+  try {
+    const parsed = new URL(raw);
+    return `${parsed.protocol}//${parsed.host}`;
+  } catch {
+    return "";
+  }
+}
+
+function resolvePublicOrigin(request: NextRequest) {
+  const fromEnv =
+    normalizeBaseUrl(process.env.AUTH_URL) ||
+    normalizeBaseUrl(process.env.NEXTAUTH_URL);
+  if (fromEnv) return fromEnv;
+
+  const forwardedHost = request.headers.get("x-forwarded-host");
+  const host = request.headers.get("host");
+  const resolvedHost = String(forwardedHost || host || "").trim();
+  if (!resolvedHost) {
+    return new URL(request.url).origin;
+  }
+
+  const forwardedProto = request.headers.get("x-forwarded-proto");
+  const protocol = String(forwardedProto || "").trim() || "https";
+  return `${protocol}://${resolvedHost}`;
+}
+
 export async function POST(request: NextRequest) {
   try {
     const session = await auth();
@@ -99,7 +129,7 @@ export async function POST(request: NextRequest) {
     const amountCents = Math.round(amount * 100);
     const payType = body.payType || dulupayConfig.defaultType || "alipay";
 
-    const defaultOrigin = new URL(request.url).origin;
+    const defaultOrigin = resolvePublicOrigin(request);
     const notifyUrl =
       dulupayConfig.notifyUrl || `${defaultOrigin}/api/payment/dulupay/notify`;
     const returnUrl = dulupayConfig.returnUrl || `${defaultOrigin}/`;