A cable sheath material comprises raw materials in percentage by weight as follows: 40%-80% of polyethylene, 5%-20% of an ethylene vinyl acetate copolymer, 15%-40% of a nanoscale composite flame retardant, 5%-20% of an assistant and 0.1%-0.5% of a crosslinking agent. Compared with a conventional cable material formed by simply mixing an intumescent flame retardant with inorganic hydroxide, the cable sheath material has better material homogeneity, common pores are avoided in the material, and the cable sheath material has better insulation and flame retardant properties.