The invention discloses a casting coating for an automobile flywheel shell, which belongs to the technical field of casting and is specifically made of the following materials: modified expanded vermiculite powder, modified white corundum powder, fused mullite, corn starch, copal resin, Terpene resin, butyl acrylate, isopropanol, microcrystalline paraffin, polyethylene glycol, polyoxyethylene polyoxypropanolamine ether, barium stearate, sodium citrate. The coating prepared by the invention has good film-forming properties, cohesiveness, high-temperature impact resistance, moisture-proof and gas-permeable properties, stable performance and excellent quality, and only needs to be coated with 1 / 4~1 / 2 of traditional coatings in actual use The dosage can ensure the normal progress of casting, and has good promotion and use value.