Screw tightening device of automatic screw locking machine

The utility model discloses a screw tightening device of an automatic screw locking machine, and particularly relates to the technical field of screw tightening devices, the screw tightening device comprises a base, a rack and an electric telescopic rod, the bottom end of the base is provided with a supporting pad, the bottom end of a connecting rod is provided with a mounting frame, and the bottom ends of the two ends of the mounting frame are provided with positioning holes; a rotating shaft is arranged in the positioning hole, a workpiece disc is installed on the inner side of the rotating shaft, and a machining head is arranged on the surface of the workpiece disc. The workpiece disc is arranged, the multiple sets of machining heads of different specifications are annularly distributed on the workpiece disc, and after the locking bolts on the surface of the mounting frame are screwed to be loosened, the workpiece disc can rotate on the inner side of the mounting frame by means of matching of the rotating