$s = '1,9,admin,你是我爱人,我是你爱人,是吗,20141109,769';
//以下任何一句都可以
echo str_replace(',', ',', $s);
echo strtr($s, array(',' => ','));
echo join(',', explode(',', $s));
//以下任何一句都可以
echo str_replace(',', ',', $s);
echo strtr($s, array(',' => ','));
echo join(',', explode(',', $s));
echo preg_replace('/([\x80-\xff]),([\x80-\xff])/', '$1,$2', $s);