To study the effects of wave on exceeding water process of underwater vehicle,the wave surface velocity of the second-order Stokes wave was coupled into the incident boundary condition,thus the unsteady numerical wave was obtained,which agreed well with the theoretical value and had high accuracy.The effects of wave on the flow field and dynamic characteristic of the underwater vehicle model when it was launched vertically under the water were investigated under fifth wave level.The results show that when the vehicle approaches the water surface,due to the induced effects of the vortices caused by the wave,the position and the size of the attached vortices at two sides of the vehicle vary significantly.The vehicle body deflects in the left under the effect of the moment rotated around the z axis in the anti-clockwise direction,so that the offset of the vehicle afterbody is about one meter when the vehicle exceeds from the water completely.