Method  Referring to the experience of the project, referring to the advanced design concept of conventional island of nuclear power plant and thermal power unit，the equipment of thermal systems of the plant would be optimized, and the control strategy of them would be optimized accordingly. It is mainly considered to the optimization of the control strategy of "startup, shutdown and bypass system" and "feed water and high-pressure heater system" in this paper.

  Result  Having 2 schemes in the control strategy of unit start-up and shutdown , having 5 schemes in the control strategy of feed water and having 3 schemes in the control strategy of bypass.

  Conclusion  Scheme I of 2 schemes of "unit start stop control strategy" has been adopted，which is simpler, less coupling than scheme II, and more reasonable in economy. Scheme II (header control) scheme of 5 schemes of "feed water system control strategy" has be adopted, which is reasonable, economical and safe for system operation; Scheme I of 3 schemes of "bypass control strategy" has be adopted, which is economical and has perfect protection control logic.