Flight simulator system modeling is different from real airborne system modeling, because we do real simulation only to the equipment that we can see in the cabin. Flight simulator system modeling is for complete air flight course and the training task. Therefore, the air data system, must carry on the modeling in principle, so as to meet with other subsystems of flight simulator data interaction, the malfunction phenomenon. Via elucidating the flight simulator system framework, we get knowledge of atmospheric data simulation system software resides and hardware drive principle. We collect the relationship of system input and output to finishing the software running processes. The method is widely used in many models of different levels in the simulator, and its functions cover simulated flight training mission requirements.