下面的代码将帮助您删除除帖子缩略图以外的所有帖子元。

    function kv_delete_all_meta_except_featuredimg(){
    $args = array( \'posts_per_page\' => -1, \'post_status\' => \'any\',  \'post_type\' => array(\'attachment\', \'page\',\'post\')); 
    $articles= get_posts( $args );

    foreach($articles as $article){
        if($article->post_type == \'attachment\'){
            $myvals = get_post_meta($article->ID);
            foreach($myvals as $key=>$val)  {

                if($key == \'_wp_attached_file\' || $key == \'_wp_attachment_metadata\'){} else {
                    delete_post_meta($article->ID, $key);

                }
            }
        }else {
            $myvals = get_post_meta($article->ID);
            foreach($myvals as $key=>$val)  {
                if($key != \'_thumbnail_id\' ){
                    delete_post_meta($article->ID, $key);
                }
            }
        }
    }


}
add_action(\'init\',\'kv_delete_all_meta_except_featuredimg\');

Note :*** 请记住，这将删除所有post元键及其关联值。因此，在继续操作之前，请先进行备份。只需在主题上添加此功能functions.php. 这里我假设你可能只有这些帖子类型attachment, post, page. 如果您有任何额外的帖子类型，请添加它。

你可以在这里阅读更多细节，我写了一篇文章。Kvcodes