An electromagnetic quick fruit grading device comprises a support frame, a main transmission device, an auxiliary transmission device, shift plate units, shift plate driving units, a shift plate reset unit and ring-shaped chains, wherein the two ends of both the main transmission device and the auxiliary transmission device are fixed with the support frame; the main transmission device and the auxiliary transmission device are mutually parallel; the two ends of the ring-shaped chains are correspondingly mounted on the main transmission device and the auxiliary transmission device to form a circulatory path; the shift plate units are mounted on the ring-shaped chains; under the driving of transmission gears of a fruit conveying chain, the main transmission device drives the ring-shaped chains to move circularly; the shift plate driving units and the shift plate reset unit are mounted on the support frame; the shift plate driving units are close to the shift plate units; the shift plate reset unit is close to one of the transmission devices; under the driving of the shift plate driving units, the shift plate units shift outwards to sweep fruit at the corresponding position on the fruit conveying chain to fall into a box body; and the shift plate units circularly move together with the ring-shaped chains and reset when passing through the shift plate reset unit.