Blow injection of coke oven gas to reduce carbon emissions; The gas injection quantity in tuyere area of blast furnace decreases with the increase of measured coke oven gas; After replacing carbon monoxide with hydrogen, the reduction degree of ore increases with the increase of hydrogen content; Increasing H2 conversion can reduce coke reactivity and save coke. The coke reaction intensity (CSR) will decrease with the increase of H2 or CO2.