The invention relates to a wooden box opener which comprises a square frame defined by a top edge, a bottom edge and two side edges. A beam is vertically installed at the lower portion of the square frame in a sliding manner. An elastic compressing mechanism for compressing the beam on the bottom edge downwards is installed on the square frame. A rope wheel type lifting mechanism capable of lifting the beam upwards is further installed on the square frame. A fixed wedge board horizontally extending out of the square frame forwards is installed on the bottom edge. A lifting wedge board horizontally extending out of the square frame forwards is installed at the bottom of the beam. The fixed wedge board and the lifting wedge board are transversely arranged in a staggered manner. The wooden box opener has the beneficial effects of being simple in structure and convenient to operate, capable of saving labor, and free of damaging the interior of a box body.