The invention provides a paperboard stacking device. The paperboard stacking device comprises a bottom plate, wherein a first paper aligning board and a second paper aligning board are arranged on the upper side of the bottom plate in parallel; universal wheels are arranged at the lower end of the bottom plate; an anti-tipping block is arranged on one side of each universal wheel; a paper aligning part is arranged on one side of the second paper aligning board; the paper aligning part can be used for pushing the second paper aligning board to move relative to the first paper aligning board; the paper aligning part comprises a bracket fixed on the bottom plate, a paper aligning board and a supporting block located on the bracket; the paper aligning board moves relative to the second paper aligning board through a screw rod mechanism; a flattening part is arranged at the top ends of the bracket and the first paper aligning board; the flattening part comprises a support; the support is provided with a pressing part; and the pressing part drives a pressing plate to move relative to the bottom plate.