For an underwater vehicle affected by actuator saturation, hydrodynamic parameters uncertainty and ocean current interference, a controller considering actuator saturation compensation and state constraint used trajectory tracking is proposed. Firstly, the horizontal trajectory tracking error equation of the underwater vehicle is constructed. Secondly, a non-linear observer is designed to estimate and compensate for model error resulting from uncertain hydrodynamic parameters and disturbances. Then, an actuator saturation compensation system, a second-order filter and a filter error compensation system are introduced and the command filtering backstepping sliding mode controller is designed to control the trajectory tracking of the underwater vehicle on the horizontal plane. Finally, the stability of the command-filtered backstepping sliding mode controller is strictly proved and the effectiveness of the controller is verified by numerical simulation.