Abstract: This task was got across the physical chemistry analyse and the hot-form experiment,researching adopt the gas-liquid multiphase balanceable energetics and dynamics by using CO₂ and O₂ mixed-blowing,and the decarbonization disciplinarian inside the metal melt in the blowing process.The composition and temperature diversification disciplinarian of iron and gas in the process of smelt was proved up.Approving the feasibility of the mixing blowing by using CO₂ and O₂ in the technics of steel-making,the theory gist of CO₂-O₂ mixing blowing technics of steelmaking was offered.According to the heat balance calculation and preliminary experi-ment,the carbon was taken off achieving the destination of metallurgy by jetting CO₂ with certain density during steel making.It was completely possible to jet certain CO₂ in blowing steel making due to the supply of energy and application of post combustion in EAF steel making.