Sheathing material with high flame retardancy and high strength

The invention discloses a sheathing material with high flame retardancy and high strength. The sheathing material comprises, by weight, 100 parts of CR/PVC, 3.5-5 parts of zinc oxide, 4-6 parts of magnesium oxide, 220.5-1.5 parts of NA, 0.5-1.5 parts of TMTD, 0.5-1.5 parts of DM, 1-3 parts of stearic acid, 2-4 parts of age resister, 10-30 parts of talcum powder, 30-50 parts of pot clay, 10-15 parts of carbon black, 10-15 parts of white carbon black, 0.5-1 parts of coupling reagent, 3-6 parts of paraffin and 8-15 parts of fire retardant. CR-PVC clay-rubber co-precipitate is adopted in the sheathing material with high flame retardancy and high strength, an emulsion copolymerization method is adopted in the sheathing material to enable CR and PVC to have a good mutual effect on the molecule level, the advantages of the emulsion copolymerization method are much better than those of an ordinary physical blending method, the processing property is excellent, and an obtained product has high product strength and better flame retardancy.