diff --git a/proxy/rewriter.go b/proxy/rewriter.go
index fd93cdc..76755a1 100644
--- a/proxy/rewriter.go
+++ b/proxy/rewriter.go
@@ -70,6 +70,27 @@ func (r *ContentRewriter) rewriteNode(n *html.Node) {
             }
         }
         
+            // 处理 <form> 标签 - 确保 action 属性存在
+            if n.Data == "form" {
+                hasAction := false
+                for i, attr := range n.Attr {
+                    if attr.Key == "action" {
+                        hasAction = true
+                        // 空 action 表示提交到当前页面
+                        if attr.Val == "" {
+                            n.Attr[i].Val = r.rewriteURL(r.baseURL.String())
+                        }
+                        break
+                    }
+                }
+            // 如果没有 action 属性，添加一个
+            if !hasAction {
+                n.Attr = append(n.Attr, html.Attribute{
+                    Key: "action",
+                    Val: r.rewriteURL(r.baseURL.String()),
+                })
+            }
+        }
         // 处理 <base> 标签
         if n.Data == "base" {
             for i, attr := range n.Attr {