您是否尝试添加筛选器以获取\\u帖子。这不是经过测试的，只是经过一点搜索后的一个想法：

 function my_filter( $query )
 {
      if( is_home() ) //Example, if u want to display recent images on home
      {
           $query->set( \'post_type\', array( \'attachment\', \'my_cpt\' ) );
      }
 }
 add_filter( \'pre_get_posts\', \'my_filter\' );

我想我会把它留在这里，以防它给你任何想法。

EDIT 2:除了在PHP中过滤之外，我能想到的唯一其他方法是自定义sql查询，然后设置post数据。例如：

$sql = "SELECT * FROM wp_posts
        WHERE post_type = \'attachment\'
        AND post_parent IN (SELECT ID FROM wp_posts WHERE post_type = \'your-cpt\')
        //ORDER BY";

 $posts = $wpdb->get_results( $sql, OBJECT );

 //loop - setup_postdata

首先，你只会得到最近修改过的CPT帖子。然后获取他们的附件。当然，您可以有一些逻辑来限制附件的数组。

$mycpt = get_posts(array(
                 \'post_type\'=>\'mycpt\',
                  \'posts_per_page\'=>-1,
                  \'orderby\'=>\'modified\'
                 ));

$attachments = array();
foreach($mycpt as $mycpt)
{
  $post_attachements = get_posts( array(
    \'post_parent\'       => $mycpt->ID,
    \'post_type\'         => \'attachment\',
    \'post_mime_type\'    => \'image\',   
    \'posts_per_page\'    => -1
) );
   foreach($post_attachements as $post_attachements){
     $attachments[] = $post_attachements;
    }

}

将此代码放入单个自定义post类型的循环中

$attachments = get_posts( array(
    \'post_parent\'       => get_the_ID(),
    \'post_type\'         => \'attachment\',
    \'post_mime_type\'    => \'image\',
    \'orderby\'           => \'menu_order\',
    \'order\'             => \'DESC\',
    \'posts_per_page\'    => -1
) );

if ( $attachments ) {
    foreach ( $attachments as $attachment ) {
        $attID     = $attachment->ID;
        echo \'<a href="\'.wp_get_attachment_url( $attID ).\'" alt="\'.apply_filters( \'the_title\', $attachment->post_title ).\'" class="att-item">\'.wp_get_attachment_image( $attID, \'thumbnail\' ).\'</a>\';
    }
}