The development of big data technology and smart grid provides support for deep mining of historical data of relay protection systems. In view of this, the operation and maintenance management system of the relay protection system based on big data is studied. This paper designs the relay protection operation and maintenance management system based on big data, and expounds the system architecture, database design, system function modules and system implementation in detail. Data visualization is performed on the basis of raw data preprocessing, which is followed by the evaluation on protective equipment in terms of both statistical and dynamic analysis. Statistical calculation of failure data, correlation analysis of defect data, operation level evaluation and condition maintenance function are then implemented. The system realizes the whole process management of relay protection equipment operation and maintenance, and finally serves the relay protection maintenance work, which is significant for reducing the blindness of maintenance, and improving the maintenance efficiency.