The invention discloses an adjustable air-suction paper-feeding mechanism. The adjustable air-suction paper-feeding mechanism comprises a front belt roller, a rear belt roller, a driving roller, a photoelectric switch, a printing rubber roller, an air-suction belt, an air chamber plate, air bellows, a hinge pin, top frames, swing arms, a swing arm shaft, cylinders and air hole switch assemblies. The two ends of the front belt roller, the two ends of the rear belt roller and the two sides of the driving roller are arranged on wall boards of the two sides respectively, the photoelectric switch is arranged in front of the printing rubber roller, the front belt roller, the rear belt roller and the driving rollers are wrapped with the air-suction belt, the air bellows of a front row and a rear row are installed below the air chamber plate, one end of the air chamber plate is positioned on the wall boards of the two sides, and the other end of the air chamber plate is arranged on the top frames; the top frames and the swing arms are fixed on the same swing arm shaft, the swing arm shaft is arranged on the wall boards of the two sides, the other end of the each swing arm is hinged to the corresponding cylinder, the cylinders are fixed on the wall boards of the two sides through fixing shafts, and the air hole switch assemblies are installed on the air chamber plate. According to adjustable air-suction paper-feeding mechanism, air suction is even, the air suction area and the air volume are adjustable, and rapid and stable conveying can be achieved whether paper is big or small.