听起来您需要对帖子内容执行一些正则表达式。可以这样做，例如：

// get the post object
$post = get_post( get_the_ID() );
// we need just the content
$content = $post->post_content;
// we need a expression to match things
$regex = \'/src="([^"]*)"/\';
// we want all matches
preg_match_all( $regex, $content, $matches );
// reversing the matches array
$matches = array_reverse($matches);
echo \'<pre>\';
// we\'ve reversed the array, so index 0 returns the result
print_r($matches[0]);
echo \'</pre>\';