The invention discloses a technology for clustering multiple nodes of a memory database of a power information system. Memory database server nodes are formed by encapsulating the memory database, and can coordinatively supply database service. A uniform access service interface is used for performing external services and simultaneously managing and scheduling the coordination and operation of the memory database nodes in a cluster. According to the technology, the defects of low access speed, instable memory database and the like of the conventional relational data are effectively overcome, and a high-efficiency and stable memory database cluster is realized. By utilizing the method, three modes of mutual backup, expansion and mutual backup and expansion are supported, so that the method is suitable for scenes with different demands.