Sorting line for sheets of different sizes

The utility model provides a sorting line for sheets of different sizes, and belongs to the technical field of automatic production equipment. The plate selecting and throwing device comprises a rackand a plurality of conveying lines arranged on the rack, the conveying lines are longitudinally stacked, and a plate selecting and throwing mechanism is correspondingly arranged on each of the other conveying lines except the conveying line at the uppermost end of the sorting line; the plate selecting and throwing mechanism comprises an air cylinder fixed to the rack, a sliding block, a swing armhinged to the sliding block, an adsorption plate fixed to the lower end of the swing arm and at least one position sensor, a plurality of adsorption holes are formed in the lower surface of the adsorption plate and communicated with the negative pressure cavity, and a guide groove is formed in the upper surface of the adsorption plate. A guide block located on one side of the swing arm is connected into the guide groove in