Internal and external epoxy coated composite steel pipes are steel pipes that are coated with epoxy resin powder by hot melt bonding on the surface of the inner and outer walls, forming a corrosion-resistant and anti-corrosion layer. When producing epoxy coated composite steel pipes, it is necessary to follow the required ratio. The surface of the coated steel pipe should be cleaned of oil, water, dust, and other pollutants in advance, and kept clean and dry. The temperature of the steel should be above 20 degrees Celsius.