Study the subject of evacuation in buildings under different exits installed.Against the evacuation path problem of crowd simulation,adopt navigation graph and agent method to solve the planning of individual path finding problem.Simultaneously in order to exhibit the collision problem in the evacuation process,built several rules to correct the penetration.At the same time use Delta3D built a complete three-dimensional crowd simulation platform under VC++9.0 IDE.At last tested three different exits conditions of different virtual environments.The simulation results show that this platform can thoroughly exhibit the movement of whole crowd,and can provide efficient data for the design of exits.