In order to predict the faults and optimize the structure of the vehicle-borne rapid-fire mortars, carry out its automat dynamic characters according to the characteristics of the new vehicle-borne rapid-fire mortars. According to the theory of multi-body dynamics, using SolidWorks and ADAMS software to establish a virtual prototype model of the automata, through the simulation of 4 consecutive shooting operations under standard charge conditions, the simulation results under continuous shooting conditions were obtained, and compared with the test results. At the same time, combined with the sequence of the artillery components, the dynamic characteristics of the recoil section and the shell were analyzed. The simulation results prove the credibility of the virtual prototype, which can provide reference for subsequent fault prediction and further structural optimization.