The invention provides a system for screening crops. The system comprises a frame, a supporting device, a fixing device, a connecting device and a collecting device. Partition plates, a first elastic plate, a first through hole, a first inclined plate, a second inclined plate and a third inclined plate are arranged on the frame. The supporting device comprises a second elastic plate, a first supporting rod, second supporting rods, first cross rods, rollers, a cam and third supporting rods. The fixing device comprises a first horizontal plate, an air cylinder, first supports, first fixing blocks, a fixing rod and a second horizontal plate. The connecting device comprises a first connecting rod, a second cross rod, a first vertical rod, a second vertical rod and a second support. The collecting device comprises a third cross rod, a baffle, a collecting box and a third support. The second elastic plate is a cuboid and is horizontally placed. The upper surface of the second elastic plate and the lower surface of the first elastic plate are fixedly connected. The cam is located below the second elastic plate. The crops can be effectively screened, screening efficiency is high, and agricultural production cost is reduced.