$url = "https://qyapi.weixin.qq.com/cgi-bin/kf/sync_msg?access_token={$access_token}";
    $data = [
        'token' => $token,
        'limit' => $limit,
    ];
    $res = $this->curl_post($url, json_encode($data));
    $res = json_decode($res, 1);
    if (isset($res['errcode']) && $res['errcode'] != 0) {
        throw new SwarmTipsException(get_tips_data('获取用户发送信息失败，错误码:' . $res['errcode'], __FILE__, __LINE__));
    }

通过上面代码获取的external_userid

//查询用户信息
$url = "https://qyapi.weixin.qq.com/cgi-bin/kf/customer/batchget?access_token={$access_token}";
$post_data = [
    'access_token'=>$access_token,
    'external_userid_list'=>$external_userid,
];
$res = $this->curl_post($url,json_encode($post_data));
$res = json_decode($res, 1);
if (isset($res['errcode']) && $res['errcode'] != 0) {
    throw new SwarmTipsException(get_tips_data('获取用户信息失败，错误码:' . $res['errcode'], __FILE__, __LINE__));
}
Log::info('查询出来的用户信息:',$res);;

查询出来的external_userid完全一致,获取的用户信息也是一模一样的