The invention discloses a weather-proof polyolefin wire cable material and a preparation method thereof, the cable material comprises the raw material by weight: 60-80 parts of LDPE, 15-25 parts of EVA, 10-15 parts of SEBS, 14-18 parts of magnesium hydroxide, 2-4 parts of stearic acid, 1-2 parts of zinc oxide, 5-10 parts of zinc borate, 1-2 parts of lead sulfate tribasic, 1-2 parts of vinyltriethoxysilane, 4-8 parts of octyl epoxy stearate, 0.5-1 part of light stabilizing agent GW-4800.5, 1-1.5 parts of anti-oxidant 215, 0.5-1 part of dibutyltin dilaurate, 0.5-1 part of dicumyl peroxide, 20-25 part of aluminum silicon black, 10-15 parts of nano barite, 5-10 parts of nano diatomite and 4-8 parts of composite filling material. The polyolefin cable material has excellent flame retardation performance, physical and mechanical properties and weatherability, can be widely used in electric power cable, communication cable, control cable, optical cable , subway cable, insulation or sheath, electronic wire, automobile and the like, and has the advantages of environmental protection and durable performance.