$content //要分离的内容

$dom = new \DOMDocument();

$arr_img_url = array();

$dom->loadHTML($content); //从字符串中加载HTML

$img_url_list = $dom->getElementsByTagName('img'); //获取图片dom

if (!empty($img_url_list)) {        foreach ($img_url_list as $key=>$item) {              $img = $item->getAttribute('src');    //获取图片地址              $img_html[]=$dom->saveHTML($item);  //把dom内容转化为html        }   }