The invention discloses a novel cutter. The novel cutter comprises a cutter handle, a mounting hole, a cutter core, a locking screw rod and a locking block. According to the novel cutter, the cutter core can be inserted into the mounting hole in the using process, and an operator can adjust the distance of the cutter core by combing with a scale plate according to the machining pore size, so thatthe machining requirement of the cutter core is met; then the locking screw rod and a second screw rod are tightened correspondingly, and the cutter core is tightly jacked in a bi-direction manner that the locking screw rod drives the locking block to jack the cutter core from the bottom to top and the second screw rod drives a second locking block to jack the cutter core from the top to bottom, so that the cutter core is fixed sufficiently; external cooling liquid can accurately flow to the cutter core through cooling water grooves in the machining process, so that efficient cooling is achieved; and the novel cutter is adopted, so that the stepless adjustment of the machining size is achieved, the situation that cutters are purchased repeatedly due to the change of the machining size is avoided, and the cost is greatly reduced.