Before processing the outer polyethylene inner epoxy coated steel pipe, the base material steel pipe must be re inspected upon arrival at the factory, and the appearance and geometric dimensions of the steel pipe must be tested. Only after passing all indicators can it be used. The outer polyethylene inner epoxy coated steel pipe is a composite steel pipe product made by sandblasting, rust removal pre-treatment, preheating, internal coating, external coating, curing, post-treatment and other processes on the base material steel pipe.