Electro galvanizing, also known as cold galvanizing in the industry, is the process of forming uniform, dense and well bonded metal or alloy deposition layer on the surface of products by electrolysis. Electroplated galvanized steel sheet, produced by electroplating method, has good processability. However, the coating is thinner and its corrosion resistance is not as good as that of hot dip galvanized sheet; Because zinc is not easy to change in dry air, and it can produce a kind of basic zinc carbonate film in humid environment. This kind of film can protect the internal parts from corrosion damage. Even if the zinc layer is damaged by some factors, the combination of zinc and steel will form a micro battery after a period of time, and the steel matrix will be protected as a cathode. The characteristics of zinc plating are summarized as follows