The invention discloses a corn scraping device which comprises a fixation base, a first screw rod, a three-claw clamping disk, a nut base, a lower slide plate, a supporting tray, an upper slide plate and a scraper mechanism, wherein bearing bases are disposed on two ends of the fixation base, and the fixation base has a first slide groove; the first screw rod is disposed on the bearing bases and driven by a first rotation mechanism to rotate; the three-claw clamping disk is fixed on the right end of the first screw rod; the nut base is meshed with the first screw rod by a nut base screw hole; the lower slide plate is disposed in the slide groove, and the left end is connected to the lower end of the nut base; the supporting tray is disposed on the right end of the lower slide plate; and the left end of the upper slide plate is connected to the upper end of the nut base. The scraper mechanism comprises a scraper base, a second screw rod, and two scraping plates, wherein the scraper base is fixed on the right end of the upper slide plate; the second screw rod is disposed on the scraper base and driven by a second rotation mechanism to rotate; the two scraping plates are disposed on the scraper base; the upper end of each scraping plate is meshed with the second screw rod by a scraping plate screw hole, and the two scraping plate screw holes have opposite rotation directions; and scrapers are disposed on the scraping plates. According to the invention, corn cobs can be scrapped and threshed automatically; and the device is safe and efficient.