Galvanized steel strip post-processing includes three aspects, phosphating, passivation, and pre-oiling. First, the passivation treatment of galvanized steel strips can improve the surface structure and gloss, improve the corrosion resistance and service life, and can improve the bonding strength of the coating and the base metal. The passivation treatment mainly adopts chromate passivation. Add some activators in the passivation solution, such as fluoride, phosphate, or sulfate, to get the chromate film thicker after the passivation. When fluoride in the passivation solution can reduce the surface tension of the steel strip, accelerate the film reaction, and can increase the chemical polishing effect so that the passive film is bright and delicate.