am i right to said all speed train from other part of china ends in Zhangjiajie Railway Station. The

As i know, all the speed train from other parts of China do not end in ZJJ Railway Station.
The airport in Changsha called Changsha Huanghua Airport, while the one in ZJJ called ZJJ Hehuang Airport.
If you mean the Hehua Airport in ZJJ, you can take a taxi to reach the Railway station in about 20 to 30 minutes.
If you mean the one in Changsha, you need to take the airport shuttle bus line 3 to reach Changsha West Bus Station where you can find the direct buses for ZJJ. Upon reaching ZJJ, you can walk to the local railway station.
There is no bullet trains service to ZJJ Railway Station.
The direct flights exist between ZJJ and Changsha.