The utility model discloses a grooving clamp for a shaft rod, wherein the hydraulic centre of the clamp is connected with a drive plate, the drive plate fixes one end of the shaft rod, and the other end of the shaft rod is fixed by a tailstock centre; a spline connection end engaged with the end part of the shaft rod is disposed at the end of the shaft rod fixed by the drive plate; and a central centre projected outwards and matched with the central hole of the shaft rod is disposed at the centre of the spline connection end. The fixture is an improvement for an old clamp, and is convenient and fast to use and operate, so that the production efficiency is increased; moreover, the manufactured products are stable and reliable in dimensions, simple in structure after the improvement, and easy to popularize and manufacture; and the fixture is suitable for all the varieties of shaft rod, and without the need to replace the fixture but with the need to preset only, thereby saving model transformation time.