Aiming at the high temperature corrosion problem of the water wall of a 350 MW low nitrogen boiler in a power plant, the simulation study was carried out to adjust the air distribution and increasing near-wall air . The relationship between the concentration of reducing gases CO, H2S and NOx in the furnace was simulated when the burn-out air rate was 38%, 33% and 27% respectively, and the effect of increasing the wall air on the concentration of reducing gases near the water wall was simulated. The results show that the burn-out air rate is reduced from 38% to 33%, which can reduce the concentration of reducing gases CO and H2S in the furnace by 20% without significantly increasing the amount of NOx, and slow down the high-temperature corrosion of the water wall. Reducing the burn-out air rate from 38% to 27% can increase the oxygen concentration in the main combustion zone, reduce the production of CO and H2S, and slow down the high-temperature corrosion of the water wall, but the NOx concentration will increase significantly. The high-temperature corrosion area in the furnace is mainly located between the UAP nozzle of the compact burnout air and the SOFA3 nozzle of the intermediate burnout air. The near-wall air can be added on both sides of the UAP nozzle of the compact burnout air. The simulation results show that the concentration of CO and H2S near the water wall can be reduced by increasing the near-wall wind with the same rotation direction as the main flow, and there is the small effect on the flow field. Due to the high concentration of CO near the water wall, the flow of near-wall air on both sides is larger, which has better effect on reducing CO near the water wall. The coverage area of near-wall air on both sides is larger for high-temperature corrosion area, while the concentration of H2S near the water wall is lower. There is no obvious difference between the single-side near-wall air and the double-side near-wall air in reducing the H2S of the water wall, but the double-side near-wall air will disturb the distribution of the flow field, which is not conducive to pulverized coal combustion.