Abstract: To meet requirements that a scene matching navigation system in vehicles of long flying time and range demands an optical imaging sensor,this paper proposes and designs a rotating varifocal mechanism using a plate traveling-wave ultrasonic motor as its driven motor.The mechanism,which is applied in an image matching system,and software and hardware combination,can obviously improve the accuracy,real-time and robust demands of the navigation system.With small room occupation,less energy loss,and high control precision,this mechanism can stably obtain various resolution images in real time.Moreover,the rotating varifocal mechanism driven by the plate traveling-wave ultrasonic motor is quick response,and the variation in loads does not affect its performance parameter.Experiment suggests that the shortest starting is less than 0.7 ms,and the shortest shutoff is less than 0.6 ms when the weight of the mechanism is 1.5 kg.The requirements of the scene matching navigation system can be met.