Abstract: In response to the problems of thermal fatigue, fin cracking, and deformation of the water-cooled wall of a certain ultra supercritical boiler, the reasons for the overheating of the water-cooled wall, large deviation in wall temperature distribution, and large rate of wall temperature change were analyzed from the perspectives of combustion side, steam water side, and automatic control strategy, and targeted treatment work was carried out. The results indicate that, in addition to the above three factors, the overheating of water-cooled walls, large deviation in wall temperature distribution, and high rate of wall temperature change are also related to the asynchronous transition between dry and wet states in different circuits. Combustion optimization adjustment, hydrodynamic optimization, and automatic control optimization have a certain effect on the high wall temperature and large rate of wall temperature change in local areas of water-cooled walls. However, they cannot completely solve the problems of large thermal load deviation on the combustion side and sensitivity to steam water side pulsation caused by the design of boilers with double tangential vertical water-cooled wall layout. To prevent thermal fatigue, fin cracking, deformation and other problems of water-cooled walls, and to avoid leakage and even non-stop accidents, it is still necessary to control the duration of low load operation, reduce the rate of load variation, adjust operating parameters, and cooperate with shutdown inspections, standardize the start stop process, and carry out water pressure tests to discover and solve water-cooled wall abnormalities in a timely manner.