Cathodic protection of zinc anodes is to protect steel equipment by connecting a metal or alloy that is more likely to lose electrons. For example: steel gate protection, some use this method. It is a more active metal, such as zinc, connected to the steel gate. In this way, when electrochemical corrosion occurs, it is the kind of metal that is more reactive than iron, and the iron is protected. Usually in the stern of the ship and in the hull below the waterline part, a certain amount of zinc block is installed to prevent corrosion of the hull, etc., is the application of this method. At present, in addition to the protection of steel equipment in seawater or river channels, electrochemical protection is also used to prevent corrosion of cables, oil pipelines, underground equipment and chemical equipment.