The invention relates to a composite wood board gluing machine. The composite wood board gluing machine comprises a bottom plate, an installing frame, a stacking device and a gluing device; the installing frame is installed on the bottom plate, and provided with a slide groove; the gluing device is installed in the slide groove, and the stacking device is arranged at the lower end of the gluing device, and installed on the bottom plate; the stacking device comprises a linear guide rail, a limiting mechanism, a supporting mechanism and a feeding mechanism; the gluing device comprises a glue outflow mechanism and a uniform smearing mechanism; and the uniform smearing mechanism comprises a sliding block, a sliding rod, a cross plate, a telescopic uniform smearing frame, a fixed supporting plate, a length adjusting cylinder, a connection ring and a driving branched chain. The composite wood board gluing machine can solve the problems that in the existing composite wood board gluing process, wood boards are stacked in disorder, gluing is not uniform, glue waste can be caused easily, and adjustability is poor, the function of performing automatic gluing on composite wood boards can be achieved, and the beneficial effects that stacking is in order, gluing is uniform, glue waste is not likely to be caused, and adjusting is flexible are achieved.