diff --git a/conststr.php b/conststr.php
index b3a6db3..8975150 100644
--- a/conststr.php
+++ b/conststr.php
@@ -105,7 +105,8 @@ $constStr = [
             'background' => 'Set an url as background photo.',
             'backgroundm' => 'Set an url as background in mobile phone.',
             'forceHttps' => 'if 1, force to redirect to https when visit via http.',
-            'littleFileCacheTime' => 'Unit is hour, if set this, little file<1M will through program and cache in explorer, otherwise, default 302 to Microsoft',
+            'fileConduitCacheTime' => 'Input number, unit is hour, if set this, little file<1M(or fileConduitSize) will through program and cache in explorer, otherwise, default 302 to Microsoft',
+            'fileConduitSize' => 'Input number, unit is M(suggest less than 4M), if set this, little file<this value will through program and cache in explorer, otherwise, default 302 to Microsoft',
             'theme' => 'Select theme for guest.',
             'timezone' => 'Set default timezone.',
             'guestup_path' => 'Set guest upload dir, before set this, the files in this dir will show as normal.',
@@ -134,7 +135,8 @@ $constStr = [
             'background' => '设置一个url作为背景。',
             'backgroundm' => '设置一个url作为手机端用的背景。',
             'forceHttps' => '0或1。如果设置为1，会强制跳https',
-            'littleFileCacheTime' => '单位是小时，如果设置，小于1M的小文件会从程序通过然后缓存在浏览器，不然，默认302跳微软',
+            'fileConduitCacheTime' => '填数字，单位是小时，如果设置，小于1M(或fileConduitSize)的小文件会从程序通过然后缓存在浏览器，不然，默认302跳微软',
+            'fileConduitSize' => '填数字，单位是M(建议4M以下)，如果设置，小于这个值的小文件会从程序通过然后缓存在浏览器，不然，默认302跳微软',
             'theme' => '为游客选择一个主题。',
             'timezone' => '设置默认时区。',
             'guestup_path' => '设置游客上传路径（图床路径），不设置这个值时该目录内容会正常列文件出来，设置后只有上传界面，不显示其中文件（登录后显示）。',