Green hydrogen is a vital component of China's new energy system. Its deployment in the steel and metallurgical industry through a robust

economical

flexible

and efficient integrated energy system is critical for achieving China's carbon peak and neutrality goals. This paper outlines the shift in research from "blast furnace hydrogen-rich ironmaking" to "shaft furnace green-hydrogen ironmaking" in steel metallurgy and reviews optimization strategies for integrated energy systems. It addresses critical challenges in low-carbon optimization

including integrated multi-energy substance flow analysis

stage-wise control

and operational efficiency. A research framework is proposed focusing on precise modeling

multi-scale control

and quantitative analysis of energy efficiency

flexibility

and risk. The paper analyzes the core components of the framework

facilitating further research in green hydrogen metallurgy. This research is poised to underpin the development of innovative integrated energy systems and inform industrial planning with essential theories and technologies

supporting the low-carbon transition of the energy and steel metallurgy sectors.