主要用到的就是 preg_match_all 函数
// An highlighted block
$str = '< img src="http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090810_54813.jpg" alt="" />< img src="http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090810_70295.jpg" alt="" />< img src="http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090811_72318.jpg" alt="" />< img src="http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090811_20048.jpg" alt="" /> </p >';
$match_str = "/[img|IMG].*?src=['|\"](.*?(?:[.gif|.jpg]))['|\"].*?[\/]?>/";
preg_match_all ($match_str,$str,$out);
var_dump($out[1]);
这样就可以了,
//输出以后就是这样
array(4) {
[0]=>
string(99) "http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090810_54813.jpg"
[1]=>
string(99) "http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090810_70295.jpg"
[2]=>
string(99) "http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090811_72318.jpg"
[3]=>
string(99) "http://upload.xxxxxx.net/http://oss-cn-hangzhou.aliyuncs.com/wc-kiascrm/20170713090811_20048.jpg"
}