Multilayer of aluminum plastic composite pipe is welded aluminum band, inner and external layers are all made of polyethylene. Special-purpose hot melting adhesive is used, and extrusion molding method is adopted for composite of pipe. Pressure resistance of metal pipe and corrosion resistance of plastic pipe are combined together on the pipe. The aluminum layer allows PE-AL-PE multilayer composite pipe to withstand high working pressure and prevent oxygen and gas from penetrating into the pipe. They are easily bent, which makes the use of numerous fittings unnecessary.