The invention belongs to the technical field of information, and particularly relates to a nuclear power plant software alarm system based on high-speed serial communication. The main structure of thesystem comprises a data access layer DAL, a business logic layer BLL, a human-computer interaction layer HMI, a software watchdog module and a data source layer. The data source layer is the bottommost layer and is used for data storage; the software watchdog module is located between a data source layer and a data access layer DAL, is a monitoring program and is responsible for monitoring work of a communication interface process and a database operation process, when the processes are abnormal, a software watchdog restarts the processes, and the stability of the system is guaranteed. The data access layer DAL is used for processing the data of the lower layer and providing the processed data for the upper layer; the business logic layer BLL is located at the upper layer of the data access layer DAL and is used for receiving the data at the lower layer, processing the data and then outputting and displaying the processed data; the human-computer interaction layer HMI is located on the upper layer of the business logic layer BLL and used for human-computer interaction. The system is more complete in function and has a good application prospect.