Abstract: Reactor protection system is a very important safety system in nuclear power plant. It is mainly used to protect the safety of reactors, the environment and personnel. It is the Class 1E instrumentation & control equipment of nuclear power plants. Its own reliability and safety play an important role in the normal operation of nuclear power plants. The architecture of the reactor protection system plays a key role in the reliability, availability and maintainability of the entire system. Based on the NASPIC platform and according to the functional requirements and design criteria of the reactor protection system, this paper proposes a relatively complete and reasonable reactor protection system architecture that meets the requirements of the functions and design criteria. At the same time, a scientific research prototype of “Hualong No. 1” was built according to the architecture design, and based on the FTA/Markov reliability analysis method, the function test and reliability analysis and calculation of the scientific research prototype of the protection system built were carried out. It proves that the architecture design of the reactor protection system meets the design requirements and provides a reference for the system architecture design of subsequent projects.