The invention relates to a reaction molding device, and particularly relates to a polyurethane foaming plastic reaction molding device. The technical problem to be solved in the invention is to provide a polyurethane foaming plastic reaction molding device with ideal reaction molding and thorough reaction. In order to solve the technical problem, the invention provides the polyurethane foaming plastic reaction molding device. The polyurethane foaming plastic reaction molding device comprises a frame body, a clapboard, a first stirring shaft, a first spiral blade, a stirring blade, a third belt wheel, a second stirring shaft, a first belt wheel, a first bearing base and others; left and right sides of the bottom part in an installing frame are symmetrically welded with supporting rods, and top ends of the supporting rod are welded with the frame body; the center of the bottom part of the frame body is welded with a discharge pipe, and a valve is arranged on the discharge pipe. Through a motor, the stirring blade is driven to rotate, so as to mix raw materials in the frame; meanwhile, the first spiral blade and the second spiral blade are driven to rotate, and thus the raw materials are vertically conveyed.