Three-layer composite asphalt anti-corrosion pipe

The utility model relates to a three-layer composite asphalt anti-corrosion pipe which mainly solves the problems that a coating of a petroleum asphalt anti-corrosion layer in the prior art is low in mechanical strength and poor in heat stability, and can not bear stabbing of plant roots. The three-layer composite asphalt anti-corrosion pipe is characterized in that an inner wall of a steel tube (1) is coated with an epoxy anti-corrosion layer (2), an outer wall of the steel tube (1) is sequentially coated with an undercoat layer (3) and an asphalt anti-corrosion layer (4), and a polyolefin protective layer (5) is wound on an outer surface of the asphalt anti-corrosion layer (4). Due to the facts that the epoxy anti-corrosion layer is coated on the inner wall of the steel tube, and the polyolefin protective layer and the asphalt anti-corrosion layer are wound on the outer wall at high-temperature, the three-layer composite asphalt anti-corrosion pipe has the advantages of being good in heat stability, and imp