diff --git a/convention.php b/convention.php
index 968595d4..2659285e 100644
--- a/convention.php
+++ b/convention.php
@@ -136,6 +136,7 @@ return [
 
     // 是否使用session
     'use_session'           => true,
+    'var_session_id'        => '', // SESSION_ID的提交变量
     'session'               => [
         'id'         => '',
         'prefix'     => 'think',
diff --git a/library/think/Session.php b/library/think/Session.php
index 13ce8c55..02fc33c8 100644
--- a/library/think/Session.php
+++ b/library/think/Session.php
@@ -39,7 +39,9 @@ class Session
         if (isset($config['prefix'])) {
             self::$prefix = $config['prefix'];
         }
-        if (isset($config['id']) && !empty($config['id'])) {
+        if (Config::get('var_session_id') && isset($_REQUEST[Config::get('var_session_id')])) {
+            session_id($_REQUEST[Config::get('var_session_id')]);
+        } elseif (isset($config['id']) && !empty($config['id'])) {
             session_id($config['id']);
         }
         if (isset($config['name'])) {