The invention relates to a piece cutting device for vertical conveying of bamboo piece green and yellow faces and belongs to the technical field of bamboo piece processing. The piece cutting device comprises a channel body enabling the green faces and the yellow faces of bamboo pieces to be placed vertically. The channel body comprises a conveying bottom face and conveying blocking edges arranged on the two sides of the conveying bottom face. The conveying blocking edges are provided with outer surface primary processing devices. A bamboo piece conveying line behind the channel body is provided with a vertical piece cutter in a matched mode. A piece dividing conveying rail which is symmetric with the piece cutter as the symmetry axis is arranged behind the piece cutter. A power stabilizing structure is arranged between the piece cutter and the piece dividing conveying rail. By means of the scheme, cutting of multiple bamboo pieces can be achieved through vertical arrangement of the blocking edges. Besides, the bamboo pieces are quickly cut and divided through a thin piece cutter. A front conveying channel used for drawing the bamboo pieces more conveniently and more efficiently is further arranged.