arrive zhangjiajie at 12.35am, after custom should be after 1am. Will there be cab at the airport?

Well, as I know, there will have several cabs at that time. However, some reviews show that the cab drivers won't use the taximeter. And the fare would be expensive at that time. Thus you are advised to take a taxi to ZJJ Bus Station and find a hotel nearby. In the next early morning, you can take the direct coach from there to Wulingyuan Scenic Area. :)