Flight flow in area is influenced by many factors,which cause airway congestion and make flight delay. In order to solve the problem of airspace tension,ConsideringSthree main factors as dangerous weather, segment capacity, military activities,combining with the concept of the airspace flexible use and building a minimum cost model of real-time dynamic allocation of flight flow is necessary. After all the shortest path of flights in the region is calculated by Floyd algorithm,and then use Matlab simulation for it.SThe result showsSthat the flow to effectively reduce the operation cost after dynamic allocation and ease the air traffic.