The utility model discloses a tachometer disk processing special fixture, anchor clamps include base, portable bushing plate, portable pressure strip and compression screw, and the base upper surface is equipped with U type recess, follow recess lateral wall top symmetry and are equipped with two slide rails, are equipped with the slider on the slide rail, slide rail and grooved underside level, and portable bushing plate one end is established on the slider of slide rail, and the portable bushing plate other end stretches to the recess, portable bushing plate and grooved underside level, portable pressure strip is established and stretch to the recess on the slide rail slider of symmetry. The utility model discloses simple structure is through the position at the slide rail of adjusting bushing plate and pressure strip to process the tachometer disk of different specifications and size, convenient to use.