This machine adopts the way of pushing forward, has the functions which change the diameter automatically, can weld the reinforcing frame of cement pipe with the end s of socket and plug type, can weld the reinforcing frame of cement pipe with the ends of flat mouth and the socket angle can be adjustable. The electirl apparatus system adopts the digital control and frequency conversion speed adjustment etc advanced means so that the presion of the complete machine have been improved. Through using it is proved that this machine is steady and reliable in performance, accurate and swift in changing diameter, simple in use and high in production efficiency. It is the outstanding model in the domestic similar equipment at present and it is the best choice of the manufacturer of drainage pipeline.