这应该可以解决问题:

$str = trim(preg_replace('/\s*\([^)]*\)/', '', $str));

请注意，与其他建议不同，此答案也消除了括号内的空白.

Note, this answer removes whitespace around the bracket too, unlike the other suggestions.

修剪是为了防止字符串以方括号开头，在这种情况下，不会删除其后的空白.

The trim is in case the string starts with a bracketed section, in which case the whitespace following it isn't removed.