Abstract: The measurement of coupling coordination development is of great significance to the study of sustainable development of iron and steel industry.In this paper, the coupling coordination degree is applied to the iron and steel industry.Firstly, the evaluation index system of the coupling coordination degree of resource-environment-economy (REE) system is constructed, and the evaluation values of resource-environment-economy system and its subsystems in China’s iron and steel industry in 2000-2018 are calculated by using the weighted TOPSIS method.Then, the coupling coordination degree model is used to analyze the coupling coordination development level of resource-environment-economy system.The results show that the comprehensive evaluation value of resource-environment-economy system of iron and steel industry presents a stable-rising-stable development trend.The coupling coordination degree has gone through a transition from barely coordination to well coordination, and the coupling coordination state has been improved continuously.