This paper studies the control problem of the tiltrotor transition mode, which requires the regulation of nacelle inclination from 0 to 90 degree based on a finite-time switching control technique. Because of the dynamic characteristic of tiltrotor conversion, a single system model can not meet the requirements for control precision. Therefore, a switched system is used to characterize the multimodes of the system. Then, based on the average dwell time method, a sufficient condition for finite-time stabilization of the longitudinal motion flight control system is developed. Finally, simulation results show that smooth transition of tiltrotor transition modes can be implemented effectively by using the proposed switching control strategy.