Abstract: To reduce the cost of circulating gas CO₂ separation and gas preheating in the process of oxygen blast furnace ironmaking, this paper put forward the technological process of remaking gasifier for oxygen blast furnace injection gasifier. Based on the method of exergy analysis, the main process exergy indices of traditional blast furnace (TBF) and OBF-RGG were calculated and evaluated. The results show that the exergy loss of the blast furnace unit and the whole system in TBF process are 0.911 GJ/tHM and 1.636 GJ/tHM, respectively; the exergy loss of the blast furnace unit and the whole system in OBF-RGG process are 0.298 GJ/tHM and 0.826 GJ/tHM, respectively; in addition, the exergy efficiency of the TBF and OBF-RGG processes are 83 % and 91 %, respectively. This process can realize joint production in metallurgical and chemical industries, and is of great significance for promoting industrial coproduction.