The utility model discloses a differential rebounding sequential rice-seedling throwing device. Wherein, an outer, a middle and an interior rotary drum are fixed together through a flange. On the drums, a plurality of coaxial holes are distributed at equal distance. Knock-out pins pass through the holes. On the knock-out pins, return springs are mounted. On a main shaft, a row of cams are arranged in phases sequentially corresponding to each circle of the knock-out pins. On a supporting shaft that is parallel with the main shaft and located between the cams and the interior rotary drum and fixed on a left and a right stationary supporting disc, a row of L-like levers are looped that are corresponding to the cams and each is provided with one torsion return spring. The shorter arm ends of the levers contact with the cams through a vertical guide rod fixed on a fixed support, the longer arm ends of the levers contact the knock-out pins through a cross guide rod furnished with a return spring. The cams on the main shaft rotate with the rotary drum in certain speed ratio. When the cam profiles reach to the lowest point, the levers will rotate with the supporting shaft under action of the torsion return spring, and the longer arm ends of the levers will push the knock-out pins through the cross guide rod, the seedlings in the outer rotary drum will be knocked out and drop freely along the guide plates into the field, which realizes sequential seedling distribution.