The utility model discloses a seed sorting machine, comprising an air pipe arranged on a rack; an air blade providing wind energy is arranged inside the air pipe, an air separation box is connected at one side of the air pipe, and a feeding hopper is arranged at the upper part of the air separation box. The seed sorting machine is characterized in that: a classifying screen bank is arranged at one side of the air separation box, and the classifying screen bank sequentially comprises a sundries screen, a seed screen and a sand screen. As the classifying screen bank consisting of the sundries screen, the seed screen and the sand screen is arranged at one side of the air separation box, so as to effectively extract the sundries and sands mixed in the sorted seeds. The seeds with light specific gravity can be extracted out through the material outlet at the lower part of the air pipe. The seed sorting machine has the advantages of simple structure, convenience in operation, low manufacturing cost and convenience in use and the like.