Abstract: Standard DI&C-ISG-04 and the functional requirements on priority management system (CIS) of ACPR1000 nuclear power unit are reviewed. Based on the experience feedback from CPR1000 nuclear power plant, difficulties in CIS design are analyzed and a scheme of RPS priority management system for ACPR1000 nuclear power plant reactor based on FirmSys is proposed. Compared with that of CPR1000 nuclear power station, the CIS for CPR1000 nuclear power plant is further optimized such as the localized design based on self-reliance, better prevention of software common cause failure, more reliable online periodic test, modular design with multiple interfaces, and onsite function design. and the design sheme has been successfully applied in ACPR1000 nuclear power station.. The practice shows that the CIS scheme proposed in this paper is a feasible scheme.