Magnesium anode products are usually used in fresh water, light salt water and high-resistivity soil environments. They are not suitable for flammable and explosive occasions, and are not suitable for environments with severe AC interference. Sacrificial anode cathodic protection is a method of using the principle of primary battery to prevent metal corrosion. The specific method is to use a highly reducing metal as a protective electrode, and connect it with the protected metal to form a primary battery. The metal with strong reducibility is used as the negative electrode of the redox reaction, which is sacrificed and consumed, and the metal is protected as the positive electrode to avoid corrosion. This consumes the anode metal and protects the cathode metal. Therefore, it is also called sacrificial anode protection method. Generally speaking, the corrosion of the anode metal is used to protect the cathode metal and slow down the corrosion.