Abstract: Aiming at the problem of large tracking error in the navigation process of new semi-submersible unmanned aerial vehicle, a tracking control method based on MPC is proposed. In this paper, the motion model of the new semi-submersible is established, and based on the actual parameters, the MPC objective function and system constraints are constructed; The trajectory tracking problem of the semi-submersible is transformed into the optimal value problem; The control algorithm is simulated and analyzed by using the simulation software, and the navigation trajectory tracking test is carried out by using the satellite positioning equipment. The simulation and test results show that the MPC based trajectory tracking control method improves the tracking accuracy of the navigation trajectory of the semi-submersible unmanned vehicle, and the tracking accuracy is about 50％ higher than the original PID control method.