The spiral seam welded steel pipe with inner and outer plastic coating is a form of anti-corrosion treatment for the inner and outer walls of the steel pipe, which effectively avoids corrosion of the steel pipe by the conveying medium or external environment. Internal and external coating can be divided into internal and external epoxy resin powder hot melt coating, internal and external polyethylene powder hot melt coating, internal epoxy resin external polyethylene hot melt coating.