On the base of discussing the control process of high pressure feed-water system for LT coal gas cooling during N2 steel -making in Bao Steel, through experimental research on dynamic characteristics of automatic circumfurence valve system, and according to the enterprise reforming practice making use of several energy saving techniques and the on-the-spot long-term running condition, the application prospect and social benefit of automatic circumfluence valves system is analysed in the paper.