The invention discloses a sheath material for an urban power cable. The sheath material is prepared from raw materials in parts by weight as follows: 50-70 parts of polyvinyl chloride, 40-50 parts of polystyrene, 30-40 parts of chloroprene rubber, 2.8-3.6 parts of a crosslinking agent, 1-2 parts of dimethyldimethoxysilane, 70-90 parts of a filling agent, 0.8-1.6 parts of diisobutyl phthalate, 1.5-2.5 parts of disproportionated rosin, 2-4 parts of microcrystalline wax, 1.5-2.5 parts of calcium stearate, 0.4-0.8 parts of barium stearate and 2-4 parts of an antioxidant agent. The sheath material has excellent mechanical performance and good heat stability, still has good hydrophobicity even in the high-temperature environment, is high in hardness and safety performance and long in quality guarantee period, can effectively relieve bending, impact and other external force functions and also can effectively maintain inside structures.