The invention discloses a buried anti-corrosion cable sheath material. The buried anti-corrosion cable sheath material comprises, by weight, 11 to 13 parts of polyvinyl chloride, 15 to 30 parts of polytetrafluoroethylene, 20 to 25 parts of epoxy resin, 10 to 15 parts of polyurethane, 5 to 10 parts of acrylic acid, 40 to 60 parts of a composite organic solvent, 20 to 30 parts of a fire retardant, and 20 to 35 parts of a foaming agent. The invention also discloses a preparation method of the buried anti-corrosion cable sheath material. The preparation method comprises following steps: S1, weighing of raw materials; S2, preparation of a solvent; S3, mixing of basic raw materials; S4, adding of the solvent; S5, adding of the foaming agent; S6, moulding; and S7, cooling. The buried anti-corrosion cable sheath material possesses durability and fire resistance, is light in weight, and is promising in popularization prospect.