Machine tool workpiece fixing device

The utility model relates to the technical field of fixing devices, in particular to a machine tool workpiece fixing device which comprises a supporting short pipe, the supporting short pipe is movably connected to the center position in a box body in a clamped mode, and a through hole is formed in the center position of the box body. Compared with the prior art, the clamping device has the advantages that the supporting short pipe, the first spring and other parts are arranged, a user puts a cylindrical material on the inner side of the supporting short pipe, the supporting rod in the supporting rod sleeve is matched with pushing of the protruding block through stretching out and drawing back of the first spring, and therefore the effect of clamping the cylindrical material is achieved; a gear ring is movably clamped in a second annular groove in one side of the supporting short pipe, one end of the gear ring is connected with a second spring and a connecting block, the whole device plays a one-way locking r