Abstract: At present, there are multiple sets of information systems in substation, which are relatively independent, and exist some problems of repeated collection, low utilization rate and difficult data sharing. These systems contain not only “four remote” structured data, but also unstructured data such as waveform, model and graphics. There is no unified storage and access interface established which hinders the improvement of intelligent level of advanced applications. To solve the above problems, a unified storage technology of multidimensional historical data of substation based on Redis and SSDB is proposed in this paper. The system includes the Redis proxy server and the SSDB storage cluster. In the proxy server, the SCADA historical data and the unstructured historical data of all substations in a region are stored in the key-value network cache library by the unified import tool supporting multi vendor and multi service history data. Then, through the proxy service program, the cache data is transferred to the distributed storage cluster. For each storage machine of the storage cluster, the cache data is stored in the disk file through the LevelDB storage engine, and the distributed permanent storage of the historical data is realized. The laboratory tests have proved that the functional requirements and performance index of the unified data storage system have reached the expected goal.