Aiming at the characters of distributed, intercurrent and asynchronism of surface to surface missile mobile launch, the Petri nets model is established. The three-dimensional model databases of missile, launch equipment and landform are established. Based on HLA, simulation system of mobile launch is designed and realized. The process of mobile launch is simulated by means of hardware and software. Model databases have nicer reusability and there is nicer interoperability in each module of simulation system. The equipment can be substituted for the simulation system as going into training.