The invention discloses a thermoplastic polyurethane elastomer cable sheath material and a preparation method thereof. The material is prepared from the following raw materials in parts by weight: 50-70 parts of thermoplastic polyurethane elastomer, 20-30 parts of acrylonitrile-styrene-acrylate copolymer, 10-15 parts of polyformaldehyde, 10-15 parts of smoked sheet rubber, 5-10 parts of boron nitride nanopowder, 12-16 parts of melamine phosphate borate, 8-14 parts of antimony trioxide, 5-10 parts of encapsulated red phosphorous, 10-15 parts of titanium dioxide, 10-15 parts of nano-fluorite, 5-10 parts of organic bentonite, 20-30 parts of acetylene black, 1-2 parts of antioxidant 1010, 1-2 parts of antioxidant DLTP, 2-3 parts of magnesium stearate, 1.5-2.5 parts of zinc stearate, 2-3 parts of zinc oxide, 1-2 parts of stearic acid, 10-15 parts of epoxy tetrahydro-dioctyl phthalate, 5-10 parts of trimellitic triacylglyceride and 3-5 parts of composite filler. The cable material has excellent comprehensive performance, has the advantages of excellent abrasion resistance, flame retardance, oil resistance, high and low temperature resistance, toughness and tear resistance, as well as excellent processing performance and electric insulation performance, is durable, and has a wide application prospect.