Abstract: The closed-loop optimization control system is capable of enhancing the automatic control quality in thermal power plants. This paper presents the requirements for the closed-loop optimization control system from domestic thermal power plants and then analyzes the architecture and effects of the imported closed-loop optimization control system in details. Based on that, it elaborates the new architecture and actual effectiveness of the domestically-manufactured system. Finally, the issues that need more attention in practice are put forward so as to provide beneficial technical reference for the power generation industry, such as self-checking, tracking and alarming functionalities in the process of switchover to DCS control.