For minimizing the total delay time, a route selection model is set up to choose a reasonable route from fixed or temporary routes for each flight reaching the intersection. And the corresponding heuristic algorithm is introduced to calculate the global optimal solution of the model. Finally three scenarios are designed to simulate the flight data of airline between Jiayuguan and Yabulai on the map. The simulation results show that the model and the algorithm can solve the optimal multiple-flight route options，and cost the minimum total delay time, thus indicating the effectiveness of the method.