这应该让您开始：

循环所有帖子并构建链接图像文件数组；交叉检查其中是否有链接到，可能需要对其进行批处理或提高超时时间；内存限制，取决于服务器；您正在处理的帖子数。

$posts = get_posts(
    array(
        \'posts_per_page\' => -1,
        \'post_type\' => array( \'post\', \'page\' ),
    )
);

$files = array();
foreach ( $posts as $post ) {
    if ( preg_match_all( \'/src=(?:\\\'|")(.+?)(?:\\\'|")/\', $post->post_content, $matches ) ) {
        foreach ( $matches[1] as $url ) {
            // Replace "wp-content/uploads/" with your upload directory if not default setup
            if ( preg_match( \'!wp-content/uploads/(.+)$!\', $url, $matches_2 ) )
                $files[] = $matches_2[1];
        }
    }
}

$posts = get_posts(
    array(
        \'posts_per_page\' => -1,
        \'post_mime_type\' => \'image\',
        \'post_type\' => \'attachment\',
        \'fields\' => \'ids\',
    )
);

update_postmeta_cache( $posts );

foreach ( $posts as $post_id ) {
    if ( is_file( $file = get_attached_file( $post_id ) ) ) {
        if ( $meta = wp_get_attachment_metadata( $post_id ) ) {
            $path = dirname( $file );

            if ( preg_match( \'!^[0-9]{4}/[0-9]{2}/!\', $meta[\'file\'], $matches ) ) {
                // Split date folders with filename for when searching size variations
                $suffix = $matches[0];
            } else {
                $suffix = \'\';
            }

            if ( ! in_array( $meta[\'file\'], $files ) ) {
                // Original file not in post content
                // unlink( $file ); 
            }

            foreach ( $meta[\'sizes\'] as $name => $data ) {
                if ( ! in_array( $suffix . $data[\'file\'], $files ) ) {
                    // Image size not in post content
                    // unlink( "$path/{$data[\'file\']}" );
                }
            }
        }       
    } else {
        wp_delete_post( $post_id, true ); // Might as well clean up
    }
}

您甚至可以使用wp_get_image_editor() &；更新旧版本src\'在您的帖子内容中动态显示。