In order to reduce the drilling force when gun drill drilling, the process while drilling by gun drill in low frequency axial vibration was dynamically simulated by using finite element analysis (FEA) software Deform3D. According to the breaker empirical formula of axial vibration drilling of gun drill, the cutting parameters were determined, the finite element model (FEM) of the machining process was processed, and the axial vibration drilling process and the general process were dynamically simulated respectively. The change conditions were analyzed and linked with axial force and torque on tool during two cutting processes, and finally the two different processing conditions were compared. The result shows the thrust force and torque occurered in the case of axial vibration drilling are reduced substantially, the drill bit wear is reduced and the service life of it prolonged.