The invention discloses a paperboard gluing machine which comprises a rack. The top faces of the two sides of a table plate of the rack are fixedly provided with two vertical plates, the bottom faces of the two sides of the table plate are fixedly provided with two support plates, the two ends of a lower transmission press roll are hinged to the two support plates, the lower transmission press roll is inserted into a long through groove formed in the middle of the table plate in a sleeved mode, and the upper portion of the lower transmission press roll stretches out the top face of the table plate; the upper portions and the lower portions of the outer side walls of the vertical plates are fixedly provided with connecting plates, the two ends of an adjusting screw rod are hinged to every two connecting plates, and the upper ends of the adjusting screw rods stretch out of the connecting plates located on the upper portions and are fixedly provided with rotary plates; the middles of the vertical plates are provided with vertical adjusting through grooves, the two ends of an upper transmission press roll penetrate through the vertical adjusting through grooves and are hinged to two adjusting blocks, and the two adjusting blocks are connected to the interiors of the corresponding adjusting screw rods in a screwed mode. According to the paperboard gluing machine, synchronous lifting and falling of the upper transmission press roll and a gluing tank can be achieved, therefore, the gluing uniformity is guaranteed, and the gluing effect is improved.