The invention discloses a sheath material for high-temperature-resistant mounting wires. The sheath material comprises, by weight, vinyl chloride, polychlorotrifluoroethylene-vinylidene fluoride copolymers, methyl vinyl ether-maleic anhydride copolymers, modified calcium peroxide, magnesium hydroxide, mica powder, ethyl vinyl ether, N-oxalation diethylene-2-benzothiazole sulfonamide, divinyl benzene, 2-crylic acid oxo di-2, 8-15 parts of 1-ethylidene ester, 0.6-1.9 parts of dibenzothiazyl disulfide, 4-cyclohexanone carboxylic acid ethyl ester, bis-[3-(triethoxy silicon) propyl] tetrasulfide, zinc stearate, calcium carbonate, carbon fiber and carbon black. The sheath material has the advantages that the sheath material is excellent in physical property, high in tearing strength and resilience property and good in high-temperature-resistant, flame-retardant and chemical-reagent-resistant properties; the modified calcium peroxide is added into the sheath material, accordingly, the sheath material is good in dispersibility and low in surface tension, and the tensile strength and various other properties of the sheath material further can be improved.