The preiron CO₂emissions in the steel industry account for over 70% of the total emissions, and reducing carbon emissions from pre iron processes is the key to achieving carbon peak and carbon neutrality in the steel industry. At present, the use of non blast furnace Tiantie gas based vertical furnace reduction technology and the optimization of various process parameters based on the pure hydrogen vertical furnace reduction process route proposed by China Steel Research Institute provide a solution for achieving low or zero emissions of CO₂in green hydrogen metallurgy.