The new power system is an energy interconnection network based on renewable energy generation. Information interconnection, data security, and reliability are the basis for the digital transformation of the power grid. Data sharing, lifecycle management, security, and user information privacy are issues that need to be addressed urgently. This paper analyzes the characteristics of the multi-combination of power grid data across services and introduces smart contract, cross-chain, and security encryption-related technologies. Based on the effective combination of smart contract and CP-ABE, data sharing schemes, including data sharing mechanism and data access control model are designed. Given this scheme, the blockchain system’s overall architecture is proposed, including the main chain, side chain, data sharing, and cross-chain information interaction. Finally, the underlying blockchain service platform is built using the Hyperledger open-source framework. We deploy the platform to verify the feasibility of the scheme according to the requirements of the data center, trust center, and blockchain-distributed nodes.