Based on the shallow water wave theory, a research scheme was proposed for liquid sloshing problems in this paper. In this scheme, the system control equations was derived using the shallow water wave theory rather than potential flow theory, and Hamiltonian system was used to express the equations. The centered finite difference and Stormer-Verlet algorithm were then used for discrete space and time, respectively. Moreover, liquid sloshing under different initial conditions were simulated and compared to obtain the main factor that affecting the nonlinear response of the system. The simulating results indicate that shallow water wave theory can effectively solve the problem of liquid sloshing. Compared with the Eulerian scheme, the Stormer-Verlet scheme had higher accuracy, while compared with the initial velocity of the vehicle, the initial displacement had more remarkable effect on the nonlinearity response of the system. It is also found that under certain conditions, liquid sloshing acted as damping in the process of the vehicle movement.