可以使用修改标签gettext 过滤器挂钩ex：

add_filter( \'gettext\', \'theme_change_label_names\');
function theme_change_label_names($translated_text){
    if (is_admin()){
        switch ( $translated_text ) {

            case \'Site Title\' :

                $translated_text = __( \'New Site Title label\', \'theme_text_domain\' );
                break;

            case \'Tagline\' :

                $translated_text = __( \'new Tagline label\', \'theme_text_domain\' );
                break;
        }

    }

    return $translated_text;
}