Emergy analysis was introduced into iron and steel industrial system. Through quantitative analysis and evaluation of energy, material, and money flows of the iron and steel industrial park, an emergy comprehensive evaluation system, which was based on the structure, function, ecological efficiency, economic efficiency, and sustainable development index, was established to quantitatively analyze the structure characteristics, ecology and economy benefits, and sustainability, and to provide theoretical basis for the construction of ecological industrial park, formulation of correct system management measures and development policies. The case study results of the iron and steel park of China indicate that the indexes after the adoption of material cycling and energy cascade are better than those of the traditional industry chain.