Abstract: This paper introduces the main problems existing in the domestic low pressure steam system of large-scale iron and steel enterprises. Based on the analysis of the system structure of low pressure steam, the mathematical models of the different steam producers are developed and the optimal regulation model (improved simplex linear programming) is set up to get the optimal way. In addition, this paper takes one iron and steel enterprise as an example and does an empirical research on the result of the optimal model. Large energy-saving potential could be achieved by the optimal operational planning.