$str = '<div align="center"> <img src="http://www.99tyg.com/public/images/e8/67/26/fc699f23244f7ca7cd360092f6ba5d641d61fe88.jpg?1476757957#h"></div>';
preg_match_all('/<img.*?src="(.*?)".*?>/is',$str,$array);
print_r($array);
$str = '<div align="center"> <img src="http://www.99tyg.com/public/images/e8/67/26/fc699f23244f7ca7cd360092f6ba5d641d61fe88.jpg?1476757957#h"></div>';
preg_match_all('/<img.*?src="(.*?)".*?>/is',$str,$array);
print_r($array);