Paper supporting mechanism with adjustable breadth

The utility model provides a breadth-adjustable paper supporting mechanism. The breadth-adjustable paper supporting mechanism is characterized by comprising an offset press body, a paper conveying roller, a first paper supporting plate, a second paper supporting plate, a lower sealing plate, a first air collecting chamber, a second air collecting chamber and an air blowing pump, the paper conveying roller is installed in the offset press body, the first paper supporting plate and the second paper supporting plate are located in the portion, below the paper conveying roller, of the offset pressbody, the first paper supporting plate is a horizontal straight line section, and the second paper supporting plate is an arc-shaped section. The first paper supporting plate, the second paper supporting plate and a lower sealing plate below the first paper supporting plate and the second paper supporting plate form a gas collecting chamber; and the air blowing pump is mounted in the middle of the lower sealing plate. Th