In order to provide an effective test bed for the rocket-assisted torpedo trajectory simulation research, according to the motion process of its trajectories, the models of the dynamics, the kinematical equation, the guidance and control equation, the wind field environment, etc. in air and under the water were built, and the object-oriented methods were applied to the simulation system design. The trajectory curves and technical parameters of characteristic points were acquired. The results show that the models are reliable, and the simulation system is exercisable.