A new approach to solve driving problems of non-contact motors in near-field acoustic levitation is presented. First, a novel piezoelectric actuator with non-contact spherical rotor is designed. Based on the structure of this actuator, the mathematical model is set up and the control equations of gas in the clearance between the stator and rotor (squeeze film) are simplified. Then, these equations, together with the control equation of rotor, are solved by using finite difference methods, and the vibration mode of pressure at stable time and revolving speed with time are evaluated. At last, a prototype of the actuator is manufactured and an experiment system is built. The experimental data agree with that of analysis results. This work will provide theoretical analysis methods of increasing revolving speed with studying on non-contact ultrasonic motors.