The invention discloses a corn thresher which comprises a case; the top of the case is connected with a threshing box; one end of the threshing box is connected with a feeding box; the inner wall of the feeding box is provided with an electric heating wire; the threshing box is internally provided with a rotary blade component; the rotary blade component comprises a rotating shaft and a screw blade arranged on the rotating shaft; a threshing bin is arranged outside the rotary blade component; the bottom of the threshing bin is connected with a corn storage box; the tail end of the rotary blade component is provided with a core discharge chamber; the bottom of the core discharge chamber is provided with a core guide hole. According to the corn thresher, the inner wall of the feeding box is provided with the electric heating wire, so that corn cobs can be rapidly dried, threshing can be better carried out, and the corn cobs are prevented from being broken in the threshing process; the rotary blade component is used for threshing in a rotating way, the threshed corns are sent into the threshing bin, and corn stalks enter the core discharge chamber; therefore, the corn thresher is high in efficiency and large in handling capacity.