The invention discloses a fully automatic corn threshing grinder, comprising a grinder body, a grinding box, a first motor, a first gear box, a second motor, a second gear box, a discharge port, a power control board, a threshing box, Feeding hopper, feeding conveyor belt, dust suction fan box, this device can automatically transport corn to the threshing box for threshing, saving manpower, feeding evenly, and preventing blockage; it can quickly thresh the corn, and then threshing the corn The granules are processed by dust removal and drying to improve the quality of corn; the waste materials after threshing are collected to prevent the waste materials from splashing into the corn and causing impurities in the corn; the dried corn can be ground into a powder device, which is convenient for packaging and storage. It is processed according to different needs; it is convenient for people to deal with waste materials without manual removal, which improves efficiency, saves time, reduces labor costs, and brings convenience to people.