Abstract: In order to improve the thermal efficiency of the gas regenerative oxidation unit, the discharged high temperature flue gas is delivered to the inlet of the unit and mixed with the raw material gas at the inlet so as to fully use the waste heat of the flue gas to improve the gas temperature at the inlet.Simulation calculation was carried out on the circulation process of the high temperature flue gas in the gas regenerative oxidation unit, and analysis was made on its influence upon the regenerative oxidation process. The simulation results showed that the flue gas circulation improved the safety of the regenerative oxidation unit, increased the flow and heat quantity of the high temperature flue gas and reduced the gas discharge from the unit.