Magnesium is a commonly used sacrificial anode material in electrochemical cathodic protection engineering, featuring high chemical reactivity and a more negative electrode potential with higher driving voltages. Moreover, magnesium surfaces are difficult to form an effective protective layer. Consequently, in aqueous media, the microcorrosion cell driving force on the magnesium surface is significant, with the protective layer readily dissolving, leading to intense self-corrosion. Hydrogen evolution reactions occur at the cathode: 2H+ + 2e- → H2. Magnesium-based sacrificial anodes include pure magnesium, Mg-Mn series alloys, and Mg-Al-Zn-Mn series alloys, all characterized by low density, high theoretical capacitance, negative potential, and low polarization. They have a high driving voltage for steel (>0.6V), making them suitable for protecting metal structures in soils and freshwater with high resistivity.