Supporting top device

The utility model discloses a supporting top device, which relates to the field of supporting of workpieces in machining and comprises an adjusting piece, two ends of the adjusting piece are respectively in threaded connection with a base and a lifting seat, the supporting top device is arranged at the bottom of a supporting object, and when the adjusting piece rotates relative to the base and the lifting seat, the base and the lifting seat can move relative to each other. Due to the fact that the base and the lifting base move relatively, compared with a traditional supporting top structure, the moving speed is increased by two times, and the height adjusting speed is greatly increased. In order to prevent the base and the lifting seat from being driven to rotate when the adjusting piece rotates, rotation stopping structures are connected to the base and the lifting seat, the rotation stopping structures are preferably polygonal guide columns, and polygonal guide holes are formed in the base and the lifting