Abstract: To accurately predict the high temperature corrosion of boiler water wall, a comprehensive high temperature corrosion model that incorporates the effects of both tube temperature and H₂S concentration was proposed. The tube temperature depends on both the gas side heat transfer and the steam side heat transfer of the boiler, which is difficult to be simulated within a single model framework due to the great dimention difference between furnace and tube. Thus, a coupled heat transfer model was developed to provide accurate prediction of tube wall temperature. This model involved a three-dimensional CFD model and a one-dimensional hydrodynamic model to separately simulate the flow and heat transfer processes of the gas and the steam sides of the boiler. The corrosion model was applied to a 350 MW supercritical boiler. Results show that local high tube temperature zones can be formed on the water wall, leading to a substantial acceleration of wall corrosion rate despite the relatively low H₂S concentration there.