Cutter and point breaking bar used on packaging box

The utility model provides a cutter and a point breaking bar used on a packaging box. The cutter comprises a main body and a saw-toothed section, wherein the edge of the cutter main body is arc-shaped; and the saw-toothed section is provided with a first saw tooth positioned in the middle, a second saw tooth which is adjacent to the first saw tooth and third saw teeth arranged at the two ends of the saw-toothed section. The edge of the cutter body of the utility model is arc-shaped and the cutter is provided with the saw-toothed section which is accordant with the size, shape and direction of the edge of the body so that neat tearing of a preservative film or aluminum-foil paper can be ensured and the advantage of convenient use is achieved. The cutter body is made of hard paper and has an environmental-friendly function. The point breaking bar comprises a point breaking bar body. An edge, which is close to the cutter, of the point breaking bar body has an arc shape matched with the cutter. The bottom edge of