The invention discloses a corn thresher. The corn thresher comprises a bottom plate, a support device, a collecting device, a fastening device, a frame, a first rubbing device, a feeding device and a second rubbing device. The bottom plate is provided with a first collecting box and a first fixing block; the support device comprises a first support, a first cross bar, a second cross bar and a first inclined bar; the collecting device comprises a first supporting rod, a first rotating shaft, a second collecting box, a first filter screen, a baffle ring and a vibrator; the fastening device comprises a first fastening rod, a first spring, a second fixing block, a second fastening rod and a gripping rod; a second inclined bar and a distributing block are provided inside the frame; the first rubbing device comprises a first roller, a first lug, a second lug, a second roller and a third lug; the feeding device comprises a feeding hopper, a centralizing block, a moving block, a pushing rod, a cylinder, a first fixing rack and a third cross bar; and the second rubbing device comprises a discharging hopper and a second fixing rack. The corn thresher provided by the invention can be used for threshing corn effectively, and is high in threshing efficiency.