The transition mode of the tilt-rotor aircraft is the most important part of the full envelope flight of the aircraft, and it is also the key to realize its complex flight function. In this paper, aiming at the design problem of the nacelle transition trajectory in the transition mode, the boundary of the transition corridor is analyzed and calculated firstly, Then, the performance indexes and constraints of the transition trajectory planning problem are analyzed and constructed in the transition corridor, and then propose a hybrid optimization algorithm combining simulated annealing algorithm and improved genetic algorithm. This hybrid approach aims to optimize the transition trajectory, ensuring both the safety of the transition mode flight and the performance of the trajectory. Finally, the designed transition trajectory’s rationality is verified by the flight simulation experiment from helicopter mode to fixed wing mode.