Aiming at the problem of poor control effect caused by complex coupling, nonlinearity and uncertainty of ultrasonic motor, a robust control method of traveling wave rotary ultrasonic motor based on practical stability was proposed. According to the dynamic characteristics of the stator and rotor of the traveling wave ultrasonic motor and the friction system, a complex nonlinear dynamic model of the traveling wave ultrasonic motor system is constructed, and the complex nonlinearity and coupling of the Hertz contact model are simplified through Taylor expansion to meet the requirements of the controller design; The influence of system uncertainty is discussed, and α synthesis is used to characterize the system uncertainty, by which a robust controller is proposed. Simulation results demonstrate the superiority of the proposed control design. The hardware in the loop Simulink simulation experimental platform is constructed, and the superiority of the controller is finally confirmed. The experimental results show that the control method is carefully designed step by step based on the model, which is versatile and can solve the complex uncertainties of all traveling wave ultrasonic motors.