With the development of informatization and intelligence of electric power information system, the information management systems of different organizations or departments are more and more dispersed, lacking effective coordination, and gradually form data silos. At the same time, the issue of data security and privacy protection has further exacerbated the phenomenon. Although the trusted computing sandbox allows multiple parties to share and process data while protecting data privacy, eliminating information barriers, it still has some limitations. In this paper, a privacy computing platform based on blockchain and trusted computing sandbox is designed for electric power information system. The trusted computing sandbox is used for privacy computing, and task scheduling and trusted supervision are realized with the help of blockchain’s decentralization, immutability and transparency. This paper provides a technical solution to solve the problem of data silos in electric power information system, which takes both security and sharing into account.