The invention discloses a cereal screening device, which comprises a substrate (1), a hopper (2), a vertical passage (3), a slanting passage (4), a fan (5), a swing plate (6), a swing rod (7), a support (8) and a transmission gear (9); the support (8) is fixedly connected onto the substrate (1), and the support (8) is sheathed with a storage bag (10) used for containing the cereals from which impurities are removed; the hopper (2) communicates with the upper port of the vertical passage (3); the lower port of the vertical passage (3) communicates with the upper port of the slanting passage (4); the lower port of the slanting passage (4) is aligned with the mouth of the storage bag (10) on the support (8); the vertical passage (3) is fixedly connected onto the substrate (1). The cereal screening device low in labor strength of farmers and high in screening efficiency is provided.