The coated composite steel pipe used in coal mine underground is a steel plastic composite pipe formed by coating a layer of polyethylene and epoxy resin powder organic matter with a thickness of 0.2-1.0mm inside and outside the steel pipe and the steel pipe itself. Coated composite steel pipes used underground in coal mines not only have the advantages of high strength, easy connection, and resistance to water flow impact, but also overcome the disadvantages of steel pipes being prone to corrosion, pollution, scaling, low strength of plastic pipes, and poor fire performance when exposed to