Comprise of plastic layer, binding layer, steel tube and plastic layer. The technique is the same as external injection steel plastic composite tube. Compared with other steel tube, plastic tube, composite aluminum plastic tube, stainless steel tube and copper tube, the new tube is more superior in sanitation index, physical/chemical performance and cost. It features corrosion resistance, aging resistance, rust-free, odor-free, toxic-free, smooth internal wall, high temperature and pressure resistance, light weight and some other characteristics. It eliminates troubles like pipe corrosion and aging and related losses in the industries. It is the ideal tube for water supply & drainage, gas supply and chemical engineering.