The invention discloses metal packaging coating and a preparing method thereof, belonging to the technical field of packaging coating. The coating includes following raw materials: bisphenol A glycidyl ether epoxy resin, modified phenolic resin, amino resin, waterborne polyurethane resin, nanometer fumed silica, pigment, silicon sol, zinc oxide, silicone acrylic emulsion, sodium borate, urea, cyclohexylamine benzoate, nanometer ferric oxide, nanometer alumina, a solvent and an auxiliary agent. The coating is prepared by softening, stirring, cooling, and other steps. The coating has excellent acid and alkali resistance, resistance to high temperature, environment protecting performance, safety and no toxicity.