The invention discloses an ultrasonic linear motor which comprises an outer tube stator, a middle tube rotor, an inner tube, a guide mechanism and a piezoelectric piece, wherein the piezoelectric piece is fixed on the outer side surface of the stator, the stator drives the middle tube rotor to rotate, the inner tube is connected with the stator through the guide mechanism, and the middle tube rotor drives the inner tube to make linear motion. The invention also discloses an automatic focusing/zooming system driven by the ultrasonic linear motor, an optical lens is inserted inside the inner tube, and a light sensing chip is fixed on a plane at the bottom part of the stator. The invention has the advantages that two-stage drive motor structure is provided, the helical motion generated by the rotor in the first-stage drive is restored to be the only linear motion of the inner tube through the second-stage drive, only the linear displacement without rotation is generated during the working process of the automatic focusing/zooming lens module, so as to meet the requirements of high pixel, and high-precision automatic focusing or zooming, and the invention still has simple and compact structure, is suitable for the miniaturization, and has high precision of the linear displacement.