The invention discloses a fireproof filling material used for a special cable, and relates to the technical field of cable processing. The fireproof filling material is prepared from the following raw materials in parts by weight: 50-60 parts of sandy soil, 20-30 parts of cordierite powder, 20-30 parts of mullite powder, 10-20 parts of asbestos powder, 10-20 parts of calcium carbonate, 10-20 parts of perlite, 20-30 parts of titanium dioxide, 15-25 parts of polyvinyl chloride, 13-15 parts of chlorinated rubber, 15-25 parts of phenolic resin, 15-25 parts of chlorinated paraffin, 10-20 parts of tributyl phosphate, 5-7 parts of zinc borate, 6-8 parts of aluminium borate, and 8-10 parts of a lubricant. The fireproof filling material has the benefits that the technological process is simple, the proportion of the raw materials is reasonable, the preparation method is simple, a high-quality filling agent is provided for the cable, the raw materials are easy to obtain, high temperature resistance is achieved, a certain flame retardancy is achieved, safety accidents caused by overhigh temperature of a cable core are avoided, the use effect is obvious, the reasonable use of the special cable is guaranteed.