diff --git a/library/think/Url.php b/library/think/Url.php
index 51e2d89c..9f725e2c 100644
--- a/library/think/Url.php
+++ b/library/think/Url.php
@@ -272,7 +272,12 @@ class Url
                 $domain .= '.' . $rootDomain;
             }
         }
-        return ($request->isSsl() || Config::get('is_https') ? 'https://' : 'http://') . $domain;
+        if (false !== strpos($domain, ':')) {
+            $scheme = '';
+        } else {
+            $scheme = $request->isSsl() || Config::get('is_https') ? 'https://' : 'http://';
+        }
+        return $scheme . $domain;
     }
 
     // 解析URL后缀