The invention discloses a diamond pencil manufacturing cutter. The diamond pencil manufacturing cutter comprises a group of cutter single pieces, wherein cutter single pieces are assembled in a spiral stacked mode, each of the cutter single pieces comprises a cutter body, a group of cutter teeth are evenly arranged at the outer edge of each of the cutter bodies, and a group of installing and positioning holes are arranged on each of the cutter bodies. Various processing requirements can be met through stacking assembly of multiple cutter single pieces, so that the flexibility is high and the replacement cost is low. The cutter teeth of the diamond pencil manufacturing cutter are made of artificial composite polycrystalline diamonds or monocrystal diamonds, and the hardness, the precision and the stability of the cutter teeth are far better than those of cutter teeth made of materials such as high-speed steel and alloys, so that processed pencils is stable in appearance specification and high in precision, the rejection rate of products can be reduced, the life and the durability of the cutter are greatly improved by the aid of the hardness of diamonds, the period of replacement of the cutter is shortened, and the production efficiency of pencil processing is improved. The cutter can also be used for manufacturing pencils in the hexangular shape, the triangular shape, the round shape, the rectangular shape, the elliptical shape and the like through changing of diamond cutter tooth silhouettes.