Abstract: The high-speed missile in water is wrapped by cavitations, which implies a heavy water-exit load. It is essential to obtain the pressure distribution as whole in order to compute the load. However, it is not possible in reality. In this paper, the water-exit process is simulated by the FEM (finite element method) liquid-solid coupling method. Based on some fundamentals of the theoretical mechanics, the impact and the impact moment are computed. Using NASTRAN, the maximum corresponding bending moments in all cross-sections are obtained. The results show that the computation in this paper can predict and assess the water-exit process of the vehicle.