The utility model provides a device of experimental on -load switch automatic switch -over of transformer semi -manufactured goods, transmission shaft that motor, both ends that includes control system and control are connected with motor pivot and on -load switch action bars respectively, set up in the adjustable base of motor bottom, control system include the rectification regulator and through the controller of rectification regulator power supply and the protection device of monitoring transmission shaft rotation state. The utility model discloses to the problem of using operating handle manual switching on -load switch in the past, provided a device of experimental on -load switch automatic switch -over of transformer semi -manufactured goods, reduced work load, shortened switch switching time, reduced manufacturing cost, promoted test efficiency, be convenient for installation and use, convenient operation is swift.