This production line is applicable to the continuous extruding of WPC/PVC door panel, clapboard 'elbow board. Proper double screw extruder, specially used for extruding wood plastic products, should be chosen in accordance with the panel section, application, and product specific gravity. Also the corresponding auxiliary machines such as vacuum calibrating platform, hauling off machine, cutting off machine, material reversing platform,etc. are equipped. Products of diversified specification can be produced with different dies.