Galvanized coil is made by using hot-rolled or cold-rolled steel strip as the substrate, removing impurities such as surface oxide scale through acid washing, and then uniformly covering a layer of zinc on the surface of the steel strip through hot-dip galvanizing or electroplating process. The zinc layer of hot-dip galvanized coils is relatively thick, usually between 60-120 grams per square meter, and has excellent corrosion resistance, which can effectively resist the erosion of harsh environments such as moisture, acid and alkali