The invention discloses a silkworm cocoon sorting machine, and relates to the technical field of natural silk production equipment. The silkworm cocoon sorting machine comprises a belt conveyor, wherein a rack is arranged at the position close to the feeding end of the belt conveyor; a sieving box is mounted on the rack through a plurality of springs; a feeding hopper is mounted at the upper end of the sieving box; a vibration motor is mounted on the outer side of the sieving box; a first screen mesh and a second screen mesh which are opposite in the inclination direction are arranged in the sieving box in a top-to-bottom spaced manner; a first cocoon discharge opening and a second cocoon discharge opening are formed in the side wall, corresponding to the lower ends of the first screen mesh and the second screen mesh, of the sieving box; the second cocoon discharge opening is positioned at the part above the feeding end of the belt conveyor; a third cocoon discharge opening is formed in the bottom of the sieving box; the discharging end of the belt conveyor is connected with a color sorter. Compared with the prior art, the silkworm cocoon sorting machine has the benefits that raw cocoons are sieved with the sieving box to be separated into three types of different sizes, cocoons of standard sizes fall into the belt conveyor and enter the color sorter to separate out yellow spotted cocoons, then all that is needed is to pick out perforated cocoons and crushed cocoons manually, the labor intensity of workers is reduced, and the cocoon sorting efficiency is high.