The zinc layer deposited from the zinc chloride-ammonia complexing agent galvanizing electrolyte has fine crystallization, beautiful luster, good dispersion and deep plating ability, and is suitable for electroplating of complex parts. This process has been widely used in China, but in production, it is found that the passive film of this type of plating solution is easy to change color, the plating solution is highly corrosive, heavy metals in wastewater are difficult to handle, and ammonia is poisonous to fish. It was gradually replaced by zincate galvanizing from the late 1970s. In order to take advantage of weak acid galvanizing. Since the 1980s, the use of ammonia-free chloride galvanizing has risen in my country, and the application of salt galvanizing has continued to decline.