The invention relates to the technical field of cable protection tubes. Particularly, the invention relates to an improved CPVC power tube comprising the following raw materials in parts by weight: 100 to 120 parts of chlorinated polyvinyl chloride, 5 to 6 parts of graphene A, 8 to 9 parts of carbon black, 6 to 8 parts of a coupling agent, 11 to 13 parts of a flexibilizer, 3 to 5 parts of a compatibilizer, 4 to 6 parts of a composite lubricant, 0.5 to 2 parts of an antioxidant, 0.5 to 1.5 parts of nano calcium carbonate, 0.5 to 1 part of titanium dioxide and 5 to 10 parts of a flame-retardantcomposite material. The melt flow rate, the tensile strength, the elongation at break and the bending strength of the improved CPVC power tube prepared by the method are relatively reduced; the cableprotection tube composed of the material has the characteristics of strong corrosion resistance, good electrical insulation, high mechanical strength, small friction coefficient, heat resistance, coldresistance, long service life and the like.