The utility model discloses a drive cam used for a rice husking machine. The drive cam used for the rice husking machine comprises an annular cam body. A drive gear array composed of drive gears is arranged on the inner side wall of the cam body. A driven gear array composed of driven gears is arranged on the outer side wall of the cam body. A locking protruded array composed of locking protrusions is arranged on the upper portion of the cam body. The locking protrusions are evenly arranged on the periphery of the cam body. A scrap discharging slot is formed in the middle of each driven gear. The locking protruded array on the cam body is used. When the rice husking machine is stopped, a user can move the drive cam to a locking position of the drive cam, clamp the locking protrusions and thoroughly prevent the drive cam from accidentally rotating so as to improve safety of the rice husking machine. In addition, as the scrap discharging slot is formed in the middle of each driven gear, scraps can be rapidly blown out and the drive cam is prevented from slipping.