composer require servo/fluidxml

    use \FluidXml\FluidXml;
    `<br />$doc = FluidXml::load($xml_file);<br />$claim = $doc->query(‘cn-claims > claim’);<br />return count($claim);`

    use Spatie\ArrayToXml\ArrayToXml;
    $xml = ArrayToXml::convert($xml_arr, [
    'rootElementName'=>"{$case['type']}专利请求书",
    ],true, 'UTF-8');