The working principle of the potato chopper is that the chopper mechanism includes a cutter head 2 and a cutter rest. The cutter head is a disk with a large diameter, and there are even rectangular frame holes on it, which are evenly distributed radially along the circumference. The holes of the frame are filled with tool holders with blades, and each tool holder is filled with a plurality of blades. In order to facilitate the inspection and replacement of the blade, an openable movable cover 6 is arranged above the cutter head, and the blade can be replaced by opening the cover. When changing knives, the cutter head should rotate slowly. In order to facilitate the rotation of the cutter head, a cutter changing motor 5 is installed to drive the cutter head to rotate slowly. In order to remove the materials blocking the blades, some disc shredders are equipped with a plurality of nozzles on the blade holder to spray compressed air to blow away the materials blocking the blades, thus improving the production efficiency of the shredders and the quality of vegetable shreds. The feeding mechanism comprises a storage barrel and a pressure plate.