In last decade, the utilization of CO2 resources in steelmaking has achieved certain metallurgical effects and the technology is matur-ing. In this review, we summarized the basic reaction theory of CO2, the CO2 conversion, and the change of energy-consumption when CO2 was introduced in converter steelmaking process. In the CO2-O2 mixed injection (COMI) process, the CO2 conversion ratio can be obtained as high as 80％ or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2, and the energy is saving and even the energy con-sumption can be reduced by 145.65 MJ/t under certain operations. In addition, a complete route of CO2 disposal technology is proposed com-bining the comparatively mature technologies of CO2 capture, CO2 compression, and liquid CO2 storage to improve the technology of CO2 utilization. The results are expected to form a large-scale, highly efficient, and valuable method to dispose of CO2.