The iron and steel (IS) industry is one of the main positions for achieving the "dual-carbon" goal, so it is significant to clarify the decoupling status (DS) of CO2 emissions and economic growth (EG) in the IS industry and the main factors affecting the DS. This paper adopted the Tapio decoupling and the catching-up decoupling to analyze the decoupling of CO2 emissions and EG in the IS industry in China during 2011–2021. Then, the ordered Logistic regression model was used to explore the key factors affecting the DS. The results showed: (1) CO2 emissions and EG both showed obvious trends of rising, falling, and then rising; (2) the Tapio DS of CO2 emissions and EG in each province continued to get better, but the catching-up DS had poorly improved; (3) R&D investment (RD), urbanization level (URB), energy consumption intensity (EI), endowment structure (ES) and environmental regulation (ER) had a significant effect on the Tapio DS, and RD and ER had a significant effect on the catching-up DS. Accordingly, the suggestions were proposed to promote the IS industry to realize the optimal decoupling of CO2 emissions and EG.