Steel enterprises, as one type of major industrial pollution source, have been facing great environmental pressure. Integrating environmental considerations into the steelmaking process is now one of the major priorities of the steel industry. A method for evaluating environmental performance is presented in this paper. The proposed method considers the procedure for environmental performance comparison of design alternatives as a multi-criteria decision-making (MCDM) problem. An integrated environmental index for the steelmaking process is proposed and qualified, utilizing the Chinese Standard (emission standard of waste pollutants for iron and steel industry). The pair-wise comparison approach of the analytic hierarchy process (AHP) is employed for solving the MCDM problem. A case study is used to illustrate how the assessment method may be applied and to demonstrate its applicability.