Abstract: The deviation of cavitation axis under maneuver conditions was investigated based on the principle of cavity expansion independence. Through computing the hydrodynamic forces acting on supercavitating vehicles, a nonlinear dynamics model of supercavitating vehicles was presented for the longitudinal plane. Regarding the problem of serious dynamic coupling and control coupling characteristics in the nonlinear system, precision linearization method was used to achieve decoupling. Then an optimal controller was designed to realize the progressive tracking in a given depth. The simulation results show that the control system is able to track depth signals effectively and possesses good control performance; supercavitating vehicles can maintain stability in cavity and have no contact with the cavity surface.