In the process of modal switching between different phases of flight, the parameters of the controller in different modes may change due to the sudden change of flight state, thus it is difficult to design a general controller to ensure the stability and smoothness of the switching process of both the modes. Direct switching between the two modal controllers may cause jumping of the control law parameters of the aircraft, and result in sudden change of the flight state, which will then affect the stability and smoothness of the modal switching process, make the system unstable and cause flight accident. In this paper, a fast double-power sliding mode switching controller based on inertia is designed taking the switching from the end climbing section to the initial cruise section as the example. Firstly, the sliding surface of the sliding mode before and after switching is used to get the sliding surface of the switching control law, and then the sliding mode switching control law is designed for the new sliding surface. Finally, the simulation results show that the fast double-power switching control method has a good tracking control effect.