Abstract: Hydrogen corrosion failure of water wall of thermal power units occurs from time to time, resulting in non-stop of units and large economic losses. In severe cases, large-area pipe explosion of water wall occurs, which brings great hidden dangers to the safe and stable operation of the unit. The mechanism and characteristics of hydrogen corrosion of water wall are analyzed and discussed. Combined with several cases of hydrogen corrosion failure of water wall in recent years, it is analyzed that the main influencing factors are water and steam quality, fluid state and pipe status, and then the corresponding preventive measures and treatment suggestions are put forward. It can effectively reduce the accidents of hydrogen corrosion failure of water wall and the adverse effects after failure.