任何主题，打开functions.php文件，将以下代码复制放到该文件最前，注意在第一个<?php 之后。
//多说官方Gravatar头像调用
function mytheme_get_avatar($avatar) {
$avatar = str_replace(array("www.gravatar.com","0.gravatar.com","1.gravatar.com","2.gravatar.com"),"gravatar.duoshuo.com",$avatar);
return $avatar;
}
add_filter( 'get_avatar', 'mytheme_get_avatar', 10, 3 );