In view of the defects in classical expert system exist that the lack of dynamic prediction function and principium illumination problem, an improved frame work of multiple rocket weapon expert system based on virtual simulation model is proposed. By building the virtual simulation model, and multiple rocket launch weapon system performance without servo system control, process control and intermittent control three control mode of the simulation analysis, and taking an example calculation. The results show that the model is feasible and effective, can provide an efficient and intuitionistic new way for solve the weapon system analysis.