In order to reduce the maximum recoil impact load of an aircraft gun in the process of launching, the virtual prototype of an aircraft gun was modeled and simulated. The 3D model of the aircraft gun was established in Solidworks, and the virtual prototype model of the aircraft gun was established by using the dynamic simulation software ADAMS based on the rigid-flexible coupling dynamics theory, and then the simulation analysis of the gun was carried out. The simulation results show that the reasonable design of the structural parameters of the aircraft gun buffer device can achieve the purpose of reducing the recoil impact load, which has a certain reference value for the optimization design of other structural parameters of the aircraft gun.