The utility model discloses a tool rest for machining a T-shaped threaded worm, and relates to the field of mechanical clamp equipment. The problems that when an existing knife rest is used for machining products of special structures such as worms with T-shaped threads, blades matched with a traditional knife rest do not exist are solved. When rough machining and finish machining are carried out,a machining task can be completed only by replacing a guide rod and a blade at the same time, the technology is time-consuming and labor-consuming, the machining cost is increased, and the productionefficiency is reduced are solved. C-shaped clamping block, the upper surface in the clamping block is parallel to the lower surface in the clamping block; a stop block is arranged in the center of the outer end surface of the sealing end of the clamping block; the horizontal plane is perpendicular to the sealing end face of the clamping block and parallel to the upper surface in the clamping block, the upper surface of the check block and the horizontal plane form an included angle of 6-55 degrees, the lower surface of the check block and the lower surface in the clamping block form an included angle of 6-30 degrees, n threaded holes 3 are formed in the upper surface of the clamping block 1 along the central axis of the short side, and n is a positive integer. The cutter holder is suitable for clamping cutters.