The invention discloses a wheel-shaped structure thread-pair driven type ultrasonic motor and a motivation method thereof, and the technical problems that an existing ultrasonic motor is small in output force and low in output power can be solved. The wheel-shaped structure thread-pair driven type ultrasonic motor comprises an outer frame, a piezoelectric actuator, an elastic wheel, a rigid wheel, an output shaft, keys and pre-tightening screws. The outer frame is of a wheel-shaped structure, the elastic wheel comprises outer grooves and inner threads, the piezoelectric actuator is of a piezoelectric stacking type, the pre-tightening screws are arranged in the outer grooves of the elastic wheel in a pre-tightening mode, the rigid wheel is a hollow threaded shaft rigid body with a key groove, the elastic wheel and the rigid wheel transmit through a thread pair, the output shaft is of a round shaft structure with a key groove, and the rigid wheel and the output shaft transmit through the keys. Alternating current signals are exerted to the piezoelectric actuator to motivate a radial micro stretching vibration mode of the elastic wheel, driving traveling waves are formed after overlaying and coupling, driving force is generated through thread pair transmission, and rotary linear output of the output shaft is achieved. The wheel-shaped structure thread-pair driven type ultrasonic motor has the advantages of being large in output force and high in output power, and has wide application prospects in the field of aerospace and the like.