Worsened mixing airflow,bad flame temperature distribution and bad combustion effect in CO Waste Heat Boiler of RFCCU Unit in Certain Petrochemical Branch Co.,SINOPEC happen in the operation.To solve these problems,the work and construction features of gas burner are analyzed,and a study on airflow pattern,airflow mixing and fundamentals of the flame stabilizing quality of gas burner is made.The gas distribution system is recalculated,a reconstruction plan is proposed.The combustion process of gas and air in gas burner before and after reconstruction are simulated based on the computational fluid dynamics software FLUENT.The simulation result indicates that flame temperature distribution is well and the combustion is perfect after reconstruction.The reconstruction plan of gas burner is reasonable and feasible.