diff --git a/app/domain/site.py b/app/domain/site.py
index f1b8b02c7..ab7275b04 100644
--- a/app/domain/site.py
+++ b/app/domain/site.py
@@ -33,6 +33,10 @@ def extract_domain(url: str) -> str:
         if domain in url:
             return domain
     _scheme, netloc = split_netloc(url)
+    if not netloc:
+        return ""
+    # Cookie Domain 常带前导点；不去掉会被当成多一级域名，无法并入站点域名。
+    netloc = netloc.lstrip(".")
     if not netloc:
         return ""
     labels = netloc.split(".")