The invention disclosed is a folding drawer made from plastic composite board, comprising two side boards, a bottom board, a back board and a cover board. The side boards, the bottom board, the back board (and the cover board) respectively include a plastic panel and an injection piece; the plastic panel and the injection piece, both extruded and formed or extruded and suction-molded, are connected by welding or gluing. The joint parts of the two side boards and the two side edges of the bottom board are respectively provided with a folding hinge which is achieved to be interconnected by the structure of the plastic extrusion panel or the injection piece. The back ends of the side boards are connected with the back board by tenons and mortises, and the front ends of the side boards are connected with the cover board also by tenons and mortises. After the adoption of the structure, the advantages of plastic extrusion, suction molding and injection molding can be realized farthest, therefore the plastic composite board folding drawer produced in the structure has the advantages of less weight, easy assembly, easy production process automatization, environment-friendliness and cyclicutilization.