在functions.php添加以下代码：

function weavatar($avatar) {
    $avatar = str_replace(
        array("www.gravatar.com/avatar", "0.gravatar.com/avatar", "1.gravatar.com/avatar", "secure.gravatar.com/avatar"),
        "weavatar.com/avatar",
        $avatar
    );
    return $avatar;
}
add_filter('get_avatar', 'weavatar');