In view of the status and problems of the airport flight slot allocation, such as flight delays, traffic jams, and resource waste, etc. this paper analyzes the game phenomenon that exist between the management department and the airlines as well as among the various airlines during the process of time slot allocation, by adopting the idea of game theory. Through the establishment of certain assumptions and game theory principle, this study build the Stackelberg game model about flight slot allocation, and obtain the Nash equilibrium, at the same time put forward the strategy model based on credibility priority. All the above are in order to realize the perfect optimization of the time slot allocation. In the end, this paper analyze the computational case according to the actual departure data of a western airport, proving that by using the game strategy model with both price and credibility to optimize, the resource utilization, fairness and allocation efficiency all have been largely improved during the process of flight slot allocation.