The invention discloses a winnowing system for shredded reconstituted tobacco, which comprises a high-frequency vibrating trough, a shredded device, a shredded device and a blanking device. The shredded device includes a feeder, a shredded machine, a shell and a frame, and The device includes a conveying pipe and a winnowing machine. The shredding machine includes a shredding cutter and a power unit. The shredding cutter includes a fast cutter disc, a slow cutter disc, a knife holder and a shredding frame bar. The fast cutter disc and the slow cutter disc are fixed side by side on the knife through bearings On the frame, the blades of the two sets of cutterheads are set alternately, the power device drives the fast cutterhead and the slow cutterhead to rotate in opposite directions at a differential speed, the cutting edges of the two sets of blades are staggered to form a shear, and the shredded frame is installed under the fast cutterhead and the slow cutterhead , including two fixedly connected arc-shaped net plates, the arc-shaped net plates are provided with a plurality of square holes for leaking wire. The invention can cut the shredded tobacco to a fixed length according to different technological requirements, avoid the phenomenon of missed beating, and carry out winnowing and purification on the shredded shredded tobacco, finally output clean shredded tobacco with uniform size and moderate length, and improve the blending uniformity of shredded tobacco products.