$zip = new \ZipArchive;
//压缩文件名
$filename = 'download.zip';
//新建zip压缩包
$zip->open($filename,\ZipArchive::OVERWRITE);
//把图片一张一张加进去压缩
foreach ($images as $key => $value) {
    $zip->addFile($value);
}
//打包zip
$zip->close();

//可以直接重定向下载
header('Location:'.$filename);

//或者输出下载
header("Cache-Control: public"); 
header("Content-Description: File Transfer"); 
header('Content-disposition: attachment; filename='.basename($filename)); //文件名   
header("Content-Type: application/force-download");
header("Content-Transfer-Encoding: binary");
header('Content-Length: '. filesize($filename)); //告诉浏览器，文件大小   
readfile($filename);