从HTML解析数据时，您实际上不应该使用正则表达式。看一下DOMXPath
Query函数。

现在，实际代码可能是：

[编辑] Stefan Gehrig为XPath提供了更好的查询，因此代码可以简化为：

libxml_use_internal_errors(true); // Yeah if you are so worried about using @ with warnings
$doc = new DomDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$query = '//*/meta[starts-with(@property, \'og:\')]';
$metas = $xpath->query($query);
$rmetas = array();
foreach ($metas as $meta) {
    $property = $meta->getAttribute('property');
    $content = $meta->getAttribute('content');
    $rmetas[$property] = $content;
}
var_dump($rmetas);

代替 ：

$doc = new DomDocument();
@$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$query = '//*/meta';
$metas = $xpath->query($query);
$rmetas = array();
foreach ($metas as $meta) {
    $property = $meta->getAttribute('property');
    $content = $meta->getAttribute('content');
    if(!empty($property) && preg_match('#^og:#', $property)) {
        $rmetas[$property] = $content;
    }
}
var_dump($rmetas);