Abstract: The thermal deviation characteristics of platen superheater in a 600 MW supercritical wall-opposed firing boiler was studied to alleviate the tube failures by overtemperature. The formation mechanism of thermal deviation in the platen superheater was analyzed, and the subsequent optimization schemes were proposed. In order to overcome the limitation by the huge scale difference between the swirl burners and furnace and incorporate the effect of burner design on the flow and thermal deviation distribution in the furnace, the flow in the burner and furnace was simulated separately, and the calculated results at the outlet of burner were taken as the inlet boundary conditions of the furnace model. Then the method of reducing the air flow rate of middle-layer burners or adjusting the air flow rate of the left-side and right-side burners was proposed to reduce the flue gas flux in the high thermal deviation area of platen superheater. Results show that the interaction between the swirling flow of adjacent burners leads to the formation of two concentrated gas streams in the furnace. As the flue gas passes through the platen superheater, its heat transfer distribution demonstrates a right-dominant double-peak shape, which is the main mechanism of thermal deviation distribution in the platen superheater. The two proposed methods can effectively decrease the peak thermal deviation in the platen superheater and dramatically lower the risk of tube failure caused by overtemperature.