The computer monitoring system centrally and uniformly manages the hydropower stations in the basin, which has high operation efficiency. The current data security sharing methods can not solve the multi-party trust problems such as data ownership and data security. In this regard, a monitoring data security sharing method for hydropower station operation and maintenance is proposed. The monitoring data of hydropower station comes from multiple independent operation systems developed by different suppliers according to different application requirements. The multi-source data are integrated and processed to meet the interactive needs of users. User permission has the characteristics of dynamic change, which can identify the permission attributes. Create a trusted container based on the user ID, locate the monitoring data, and trace the source in data sharing and storage. The access policy is formulated by the data user and bound with the private key, while the data is given an attribute set during encryption. Each data user has a corresponding access policy and a private key corresponding to the access policy, so as to realize the security sharing of monitoring data. The test results show that the design method in this paper can effectively reduce the communication overhead and storage overhead, and has good computing performance.