The invention relates to a high-flame-retarding composite material for a new energy source high-tension cable. The high-flame-retarding composite material is prepared according to the following raw material formula: 5 to 25 parts of polyvinyl resin, 25 to 50 parts of a polyolefin elastomer, 30 to 50 parts of an ethylene-vinyl acetate copolymer, 8 to 20 parts of chlorinated polyethylene, 30 to 60 parts of a compound flame retardant, 0.2 to 15 parts of a wear-resisting and flame-retarding synergist, 0.7 to 2.5 pats of an antioxidant, 1 to 2 parts of a lubricant and 1.5 to 3 parts of a cross-linking sensitizing agent. By improving a formula, a mixture of double-peak polyethylene and high-density polyethylene with a high melting index is used as polyethylene resin and the chlorinated polyethylene is used as a modifier; the ethylene-vinyl acetate copolymer is added; meanwhile, substances including the compound flame retardant, the flame-retarding synergist, the antioxidant and the like are additionally arranged, so that the composite material provided by the invention has a better flame-retarding property and can be subjected to UL94 V0-grade combustion; meanwhile, the high-flame-retarding composite material keeps the characteristics of flexibility, high-temperature resistance, oil resistance, flame-retarding performance and the like of an automobile high-tension cable material and has excellent extrusion process performance.