您可以这样使用本机WordPress codex调用（源代码http://badlywired.com/technical-stuff/2014/11/10/code-to-delete-all-images-from-wordpress-or-nearly-all/ )

<?php
/*  create this code in a file in the main wordpress directory e.g. delmedia.php
and access it via mydomain.com/delmedia.php
*/
// Include the wp-load\'er
include(\'wp-load.php\');
$args= array(
\'post_type\'      => \'book\', // obvious
\'posts_per_page\' => -1            // get them all 
);

// get all attachments post ids
$posts = get_posts( $args );
foreach ($posts as $post_id) {
   // get an array of image data
   $image_attributes = wp_get_attachment_image_src( $post_id->ID );
   if (strpos($image_attributes[0], \'mystring\') !== FALSE){
   echo \'Image Found : \'.$image_attributes[0];
   if (false === wp_delete_attachment( wp_delete_attachment( $post_id->ID, true     ) ) ) {
       echo \' and delete failed!<br>\';
     } else {
       echo \' and delete succeeded!<br>\';
     }
   }
}
?>

在此结合两种方法：

$args = array(
\'post_type\' => \'attachment\',
\'numberposts\' => null,
\'post_status\' => null,
\'post_parent\' => $post_id
);

$attachments = get_posts($args);
if ($attachments) {
DELETE FROM wp_postmeta
WHERE post_id IN
(
SELECT id
FROM wp_posts
    WHERE (post_type = \'book\')
)
;
    }
};

DELETE FROM wp_posts WHERE (post_type = \'book\')