The material of the intermediate joint FRP shell is mainly composed of unsaturated resin, curing agent and other additives, which has the characteristics of high mechanical strength, light material weight, corrosion resistance, long service life, high insulation strength, flame retardant resistance, good sealing, etc., and the product is safe and beautiful. Used outside the intermediate joint copper shell, the inside is filled with cable insulation glue (polyurethane two-component elastic glue), which has waterproof, impact-proof, flame retardant and other effects, and plays an external protection role on the intermediate joint copper shell.