Currently, the research of GIS and environmental models has made great progress, but the combination of both is still a difficulty. Aiming at the integration of GIS and environment model, the paper drew some functional components from open source geographic information system, and embedded the atmosphere environment model into GIS as application program interface by hybrid programming, achieved the effective integration of GIS and models, constructed the simulation platform. During the designing process, we used a number of key technologies to optimize the platform, such as design of SQLite-based database systems, Gaussian coordinate conversion, design of simulation run management software based on multi-threaded, improved the efficiency of simulation. Finally, take Beijing haze for example to verify the effectiveness of the platform, tests show that the simulation result is reasonable and effective, and the platform runs more efficiently.