Combined with many years of researching and developing experience of HKPE/PVC double-wall corrugated extrusion line, we develop PP double-wall corrugated pipe extrusion line, adopting SIMENS man-machine control system, with many advantaged characters, such as high automation, stable operation and high output. Sole out line pipe expanding machine improves the working efficiency of the production line. The appearance of this kind of product highly improves and develops the application field of corrugated pipes.