diff --git a/src/handlers/payment.rs b/src/handlers/payment.rs
index 58ba62c..f33f17e 100644
--- a/src/handlers/payment.rs
+++ b/src/handlers/payment.rs
@@ -596,6 +596,9 @@ pub struct PaymentPageQuery {
     /// JWT: 从 URL 参数传入（外部浏览器无 Cookie 时使用）
     #[serde(default)]
     pub jwt: Option<String>,
+    /// 复用已有待支付订单的 order_no（不创建新订单）
+    #[serde(default)]
+    pub resume: Option<String>,
 }
 
 #[get("/payment/page")]
@@ -615,18 +618,38 @@ pub async fn payment_page(
     let pkg = get_package_info(&query.package_)
         .ok_or_else(|| AppError::BadRequest("无效的套餐类型".to_string()))?;
 
-    let order_no = Uuid::new_v4().to_string();
-    let expires_at = pkg.days.map(|d| Utc::now() + chrono::Duration::days(d));
+    // 复用已有待支付订单（如果提供了 resume order_no）
+    let order_no = if let Some(ref resume_no) = query.resume {
+        let existing: Option<(i32, String)> = sqlx::query_as(
+            r#"SELECT user_id, status FROM payment_orders WHERE order_no = $1"#,
+        )
+        .bind(resume_no)
+        .fetch_optional(pool.get_ref())
+        .await
+        .map_err(|e| AppError::Database(format!("查询订单失败: {}", e)))?;
 
-    db::create_payment_order(
-        pool.get_ref(),
-        claims.user_id,
-        &order_no,
-        &query.package_,
-        pkg.amount,
-        expires_at,
-    )
-    .await?;
+        match existing {
+            Some((uid, status)) if uid == claims.user_id && status == "pending" => {
+                resume_no.clone()
+            }
+            _ => {
+                // 订单不存在/不属于该用户/已支付 → 创建新订单
+                let new_no = Uuid::new_v4().to_string();
+                let expires_at = pkg.days.map(|d| Utc::now() + chrono::Duration::days(d));
+                db::create_payment_order(
+                    pool.get_ref(), claims.user_id, &new_no, &query.package_, pkg.amount, expires_at,
+                ).await?;
+                new_no
+            }
+        }
+    } else {
+        let new_no = Uuid::new_v4().to_string();
+        let expires_at = pkg.days.map(|d| Utc::now() + chrono::Duration::days(d));
+        db::create_payment_order(
+            pool.get_ref(), claims.user_id, &new_no, &query.package_, pkg.amount, expires_at,
+        ).await?;
+        new_no
+    };
 
     let base_url = std::env::var("APP_BASE_URL")
         .unwrap_or_else(|_| "https://dev.xmclassmate.top".to_string());