Abstract: In order to optimize and improve the protection system architecture of current CPR1000 power plant,protection system of Ling’ao II and Hongyanhe as representative of the power stations are studied,and both the advantages and disadvantages are analyzed.By combining the advantages of both,a new protection system architecture is designed to enhance the reliability of the design.This architecture has many advantages compared with Ling’ao II and Hongyanhe,such as the separation between operation of safety equipments and non-safety system,and the separation between automatic control station and manual control station of engineered safety feature actuation system,and the countermeasures against common cause failure of DCS.