XPS plastic-extruding heat-preservation production line fits for producing XPS (polystyrene) foaming board and is one kind of high-efficient plastic extruder with high automatization, fast speed, easy operation, all of its economic and technical indexes have reached advanced level in the world. Products manufactured by this machine have low capacitance, high intensity and elegant surface. Depending on wide applicable range, foaming heat-preservation boards and sheets can be produced if relevant die heads are equipped.