Distributed control system (DCS) is widely used in industrial process control. As a matter of fact, the database in DCS is of great importance for the safety and reliability of the whole system. This paper focuses on the distributed real-time database in a dedicated DCS used to a small nuclear power station. A database which runs under Vxworks embedded operation system and can satisfy the basic database requirements was established by using the RDM Embedded database management system which reduces the operation system resources consumption. Three redundant databases are running in three distributed embedded computers, and the UDP protocol is used to implement their synchronization and the data transmission from low level computers to them. This system architecture is able to enhance the database reliability and the overall system performance. Experimental testing results show that the developed redundant databases structure running in three embedded computer called operator stations is efficient and reliable to manage real-time data, and it can meet its function and performance requirements in small nuclear power plant.