The invention relates to a passivation skin film agent special for an aluminum product and a preparation method of the passivation skin film agent. The passivation skin film agent comprises the following raw materials in parts by weight: 10-20 parts of hexafluorozirconic acid, 6-12 parts of phytate, 2-4 parts of high-molecular compound, 10-20 parts of water soluble resin, 4-6 parts of a silane coupling agent, 4-6 parts of titanium dioxide and 12-14 parts of a chelating agent, wherein the high-molecular compound is a mixture of 2,3,5,6-tetramethyl-1,4-dioxy heterocyclic group-2,5-glycol, polyvinyl alcohol and polyethylene glycol. The passivation skin film agent is a non-toxic harmless water base treatment product, can rapidly form a compact skin film on the surfaces of aluminum and aluminumalloy through a spraying or soaking manner, has excellent anti-oxidation effect, enlarges the adhesive force of a coating and a matrix and improves the corrosion resistance of the coating.