NOVELTY - A sheath material contains 61-70 pts. wt. ethylene-vinyl acetate resin, 14-20 pts. wt. poly(ethylene terephthalate), 2-3 pts. wt. carbon black, 2-3 pts. wt. zinc methacrylate, 1.2-2 pts. wt. potassium perfluorobutanesulfonate, 0.4-0.6 pt. wt. di-n-octyl bis(isooctyl thioglycolate), 2-4 pts. wt. dimethyl carbonate, 7-10 pts. wt. triethylene glycol dioctanoate, 1-2 pts. wt. 1-methyl pentanol, 0.6-1 pt. wt. antioxidant 264, 10-13 pts. wt. calcium sulfate whisker, 1-2 pts. wt. light stabilizer 770, 0.4-0.7 pt. wt. antioxidant RD and 7-11 pts. wt. modified filler, as raw materials.    USE - Sheath material is used for photovoltaic cable.    ADVANTAGE - The nontoxic sheath material has excellent heat resistance, ozone resistance, crack resistance, weather resistance and durability, and is safely prepared with high reliability by environmentally-friendly process.    DETAILED DESCRIPTION - A sheath material comprises 61-70 pts. wt. ethylene-vinyl acetate resin, 14-20 pts. wt. poly(ethylene terephthalate), 1-2 pts. wt. camphor oil, 2-3 pts. wt. N330-type carbon black, 2-3 pts. wt. zinc methacrylate, 1.2-2 pts. wt. potassium perfluorobutane sulfonate, 0.4-0.6 pt. wt. di-n-octyl bis(isooctyl thioglycolate), 2-4 pts. wt. dimethyl carbonate, 7-10 pts. wt. triethylene glycol dioctanoate, 1-2 pts. wt. 1-methyl pentanol, 0.6-1 pt. wt. antioxidant 264, 10-13 pts. wt. calcium sulfate whisker, 1-2 pts. wt. light stabilizer 770, 0.4-0.7 pt. wt. antioxidant RD and 7-11 pts. wt. modified filler, as raw materials. The modified filler is obtained by adding 1-2 pts. wt. sodium tripolyphosphate to water, stirring, adding 2-3 pts. wt. calcium silicate and 10-13 pts. wt. fly ash, heating at 60-80 degrees C, then adding 4-6 pts. wt. polyurethane acrylate, stirring for 4-8 minutes at 100-200 rpm, adding 15-20 pts. wt. linear low-density polyethylene and 24-30 pts. wt. diatomite, milling for 10-20 minutes, adding oxidized polyethylene wax, stirring, drying and grinding. The addition amount of water is 8-10 times the amount of sodium tripolyphosphate. An INDEPENDENT CLAIM is included for preparation of photovoltaic cable sheath material, which involves mixing raw materials, melt-extruding, cooling and granulating.