The motorized nosepiece objective of a microscope objective lens driven by an ultrasonic motor needs to quickly and accurately switch with compact structure. In light of ultrasonic motor direct driving, a sensor of structure with two parallel photo-couplers was proposed. Based on the structure, a combination of predictive control methods was proposed to achieve high accuracy and detect direction of rotation. Based on the classical proportion, integration and differentiation(PID) control and fuzzy control strategies, a predictive control method combining macro-control and micro-control was proposed to quickly and accurately realize switch revolving nosepiece. The control algorithms and strategies implemented in embedded control systems were used in the switch experiment. Experimental results show that with the proposed structure and control method, repeat positioning accuracy of the motorized nosepiece was less than 0.015° and positioning time was less than 3 s, which meets the requirement of motorized nosepiece repeat positioning accuracy of the automated microscope system.