Extrusion forming die for double-layer axial hollow wall pipe

The utility model discloses an extrusion forming die for a double-layer axial hollow wall pipe. The extrusion forming die comprises an outer guide die, an inner fixed die coaxially arranged in the outer guide die, and a hollow-structure core die arranged between the forming ends of the outer guide die and the inner fixed die, a forming space used for forming the outer wall and the inner wall of a product is reserved between the hollow-structure core mold and the outer guide mold and between the hollow-structure core mold and the inner fixed mold, a first-stage vent hole used for conveying compressed cold air to the hollow-structure core mold is vertically formed in the forming end of the outer guide mold, and a stepless speed regulating device is installed in the first-stage vent hole. The utility model aims to solve the problem that the inner wall and the outer wall of the HDPE hollow pipe are adhered together in the production process, so that the complete double-layer axial hollow wall pipe with the sectio