At present, the source control and end - of - pipe treatment technologies of SO₂, NO_x and other harmful gases in the flue gas of domestic iron and steel industry are mature, especially the processes of coking, sintering and pelletizing have achieved ultra - low emissions. In the context of global decarbonization, greenhouse gas control centered on carbon footprint reduction and carbon emission reduction has become the new normal, and innovation of iron and steel metallurgy technology and cutting - edge technology R&D have become the new trend of transformation and upgrading of traditional steel industry. Hydrogen instead of carbon is an important direction for future low carbon technology and energy change. Based on the mature gas - based shaft furnace, the direct reduction of hydrogen - rich or pure hydrogen gas - based shaft furnace is the non - blast furnace ironmaking technology that should be fully developed in China. Meanwhile, based on the mainstream sintering - blast furnace long - process smelting process, the layout development of hydrogen - rich low - carbon technology fueled by gray hydrogen, blue hydrogen and green hydrogen is the key to realize green and sustainable development of steel industry.