Blue-white passivator of high-salt-spray-tolerance zinc coating and preparation method and passivating treatment method of blue-white passivator

The invention provides blue-white passivator of a high-salt-spray-tolerance zinc coating and a preparation method and passivating treatment method of the blue-white passivator. According to the passivator, deionized water is adopted as a solvent, and solute comprises, by concentration, 10-20 g/L of chromic nitrate, 2.5-4 g/L of oxalic acid, 2-4 g/L of malic acid, 1.5-3 g/L of nitrilotriacetic acid, 3-5 g/L of potassium hydroxide, 2-3 g/L of cobalt nitrate, 0.5-0.8 g/L of sodium tungstate, 0.25-0.4 g/L of lanthanum nitrate and 0.4-4 g/L of gamma-aminopropyltriethoxysilane. According to the passivator, no hexavalent chromium is included in passivating liquid, and meanwhile the salt spray tolerance and corrosion resistance of a galvanized piece are improved to a large degree; meanwhile, the galvanized piece is provided with an attractive blue-white film layer, and decoration performance is improved; and the preparation method and the passivation operation process are simple, and control is easy.