The invention discloses a halogen-free environmentally-friendly power cable material for wind power generation, and its preparation method. The cable material comprises the following raw materials, by weight, 90-110 parts of a polyolefin elastomer (POE) 8450/American DuPont, 50-60 parts of PVC resin powder, 40-60 parts of wollastonite powder, 60-80 parts of nanometer attapulgite, 50-80 parts of ethylene-propylene-diene terpolymer rubber, 40-50 parts of nitrile butadiene rubber, 20-30 parts of nanometer pottery clay, 30-40 parts of aluminum hydroxide, 1-4 parts of precipitated white carbon black, 60-80 parts of light calcium carbonate, 3-5 parts of insoluble sulfur, 1-4 parts of triallyl isocyanurate, 3-5 parts of an antiager TPPD, 4-6 parts of dicumyl peroxide (DCP), 3-8 parts of dibasic lead phosphite, 5-7 parts of an antioxidant 1010, 2-5 parts of monoglycerin stearate and 50-70 parts of antimony trioxide. The cable material has the advantages of simple preparation method, excellent electrical property, good heat, ageing and wear resistances, small swelling deformation at a high temperature, secondary vulcanizing processing benefiting, low smoke and fire resistance, and environmental protection and safety.