/**
     * 身份证认证
     *
     * @param $idcard
     * @return bool
     */
    public function idcard_checksum18($idcard){

        $mainlandResult = false;
        $hongKongResult = false;
        $macaoResult = false;
        $taiwanResult = false;

        //大陆身份证判断
        if(strlen($idcard) ==18 ){
            $idcard_base=substr($idcard,0,17);

            if($this->idcard_verify_number($idcard_base)!=strtoupper(substr($idcard,17,1))){
                $mainlandResult = false;
            }else{
                $mainlandResult = true;
            }
        }

        //香港身份证
        $hongKongNumber = $idcard;

        if( strpos($hongKongNumber, "（") || strpos($hongKongNumber, "）") || strpos($hongKongNumber, "(") || strpos($hongKongNumber, ")") ){
            $hongKongNumber = str_replace('（', '', $hongKongNumber);
            $hongKongNumber = str_replace('）', '', $hongKongNumber);
            $hongKongNumber = str_replace('(', '', $hongKongNumber);
            $hongKongNumber = str_replace(')', '', $hongKongNumber);
        }

        if (preg_match("/^[a-zA-Z][0-9]{6}[0-9aA]$/", $hongKongNumber)) {
            $mul = 8;
            $sum = (ord(strtoupper($hongKongNumber))-64) * $mul;
            while($mul>1) {
                $sum += intval(substr($hongKongNumber, 8 - $mul, 1)) * $mul;
                $mul --;
            }
            $chksum = dechex(strval(11-($sum % 11)));//dec to hex
            if ($chksum == 'b') {
                $chksum = 0;
            }
            if($chksum == strtolower(substr($hongKongNumber, 7, 1))){
                $hongKongResult = true;
            }
        }

        //台湾身份证
        $taiwanId = $idcard;
        $d1 = substr($taiwanId,0,1);
        if( strlen($taiwanId) == 10 ) {
            if(stristr('ABCDEFGHJKLMNPQRSTUVXYWZIO',$d1) !== FALSE) {
                if( in_array(substr($taiwanId,1,1),[1,2])){
                    if(is_numeric(substr($taiwanId,1,9))){
                        $num = array (
                            'A'=>'10','B'=>'11','C'=>'12','D'=>'13','E'=>'14','F'=>'15','G'=>'16','H'=>'17','J'=>'18','K'=>'19',
                            'L'=>'20','M'=>'21','N'=>'22', 'P'=>'23','Q'=>'24','R'=>'25','S'=>'26','T'=>'27','U'=>'28', 'V'=>'29',
                            'X'=>'30','Y'=>'31','W'=>'32','Z'=>'33','I'=>'34','O'=>'35',
                        );
                        $n1 = substr($num[$d1],0,1)+(substr($num[$d1],1,1)*9);
                        unset($num,$d1);
                        $n2=0;
                        for($j=1;$j<9;$j++) {
                            $d4=substr($taiwanId,$j,1);
                            $n2=$n2+$d4*(9-$j);
                        }
                        $n3 = $n1+$n2+substr($taiwanId,9,1);
                        if(($n3 % 10) == 0) {
                            $taiwanResult = true;
                        }
                    }
                }
            }
        }

        //澳门身份证
        $macao  = "/^[157][0-9]{6}\([0-9]\)$/";
        preg_match($macao,$idcard,$macaoMatch);
        if($macaoMatch){
            $macaoResult = true;
        }

        if($mainlandResult || $hongKongResult || $macaoResult || $taiwanResult ){
            return true;
        }

        return false;

    }

    // 计算身份证校验码，根据国家标准GB 11643-1999
    public function idcard_verify_number($idcard_base){
        if(strlen($idcard_base)!=17){
            return false;
        }
        //加权因子
        $factor=array(7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2);
        //校验码对应值
        $verify_number_list=array('1','0','X','9','8','7','6','5','4','3','2');
        $checksum=0;
        for($i=0;$i<strlen($idcard_base);$i++){
            $checksum += substr($idcard_base,$i,1) * $factor[$i];
        }

        $mod=$checksum % 11;
        $verify_number=$verify_number_list[$mod];
        return $verify_number;
    }

如上图所示，idcard_checksum18($idcard) 方法适合大陆、香港、澳门、台湾四地身份证校验。