The general content of high sulfur nickel is 0.12~~0.25%. This kind of nickel has higher electrochemical activity than copper, copper-tin alloy, dark nickel, bright nickel, semi-bright nickel, chromium, etc. The high-sulfur nickel coating is mainly used in the middle layer of the anti-protection-decorative combined coating of steel and zinc alloy substrates. The principle is that the upper layer of nickel has a higher sulfur content than the lower layer of semi-bright nickel, thus making the potential difference between the two layers reach 100~~140mV, so that the double-layer nickel changes from the longitudinal corrosion of the single-layer nickel to the transverse corrosion, forming an electrochemical protection effect on the steel substrate.