A multi-target driving automatic conversion device for a stereo garage realizes the parking and driving process of a car by the meshing and separating of a sliding gear and a driving gear under the condition that one motor controls n (being not less than 2) rows of car loading units (comprising m (being not less than 2) layers of car loading plates) to lift. In the meshing and separating process of the sliding gear, the step motor is controlled to work by a single-chip microcomputer to drive a cylinder cam mechanism to rotate; and a groove is arranged on the cylinder cam, and a small slider slides in the groove to drive a poking fork to horizontally move, thus realizing the meshing of the sliding gear and the driving gear. The electronic reversing mechanism replaces the traditional moving mode of the sliding gear controlled by a piston hydraulic cylinder with the cylinder cam mechanism, thus reducing the cost and avoiding the effect of problems of liquid leakage, unstable transmission ratio and easy limitation due to temperature caused by the hydraulic transmission device. The stable work of the driving system is ensured, automatic conversion is realized, and the application range of the stereo garage is improved.