Supercavitation can be viewed as a phenomenon that could boost the speed of underwater vehicles. The vehicle is entirely surrounded by the cavity while it is traveling underwater in the supercavitation stage. Thus, the vehicle actually travels in air and has very small skin friction drag. Hydrodynamics and stability of the supercavitating vehicle do not depend on the hydrodynamic coefficients as in the case of a fully wetted underwater vehicle. The contact of the aft of the vehicle with the cavity wall get rise to the nonlinear planning force. And it is really hard to control and moneuver a supercavitating vehicle. This paper analysed the hydrodynamic force of all parts of the supercavitating vehicle. The efficiency of fin while it is traveling underwater are computed. The nonlinear dynamics model of supercavitating vehicle is completed. The controller are designed by nonlinear switched control strategy.