Plastic-lined steel pipes, based on galvanized seamless steel pipes or welded steel pipes, with the inner weld ribs removed, a food-grade polyethylene (PE) pipe of the same diameter as the galvanized pipe is inserted. The thickness of the polyethylene lining must meet the HG/T 20538-2016 standard. After a certain period of pressure and heat treatment, it is shaped into a product that is an upgraded version of the traditional galvanized pipe.