In order to solve the problems of energy data tampering, leakage and data ownership disputes in the process of data sharing between enterprises and departments of energy internet, combined with the characteristics of blockchain-traceability and hard to be tampered with, an energy data access control method based on blockchain multi-chain architecture was proposed, which can protect user privacy and realize cross-enterprise and cross-department access control of energy data at the same time. In this method, the combination of supervision chain and multi-data-chain was used to protect the privacy of data and improve the scalability. The method of storing data on the chain and storing original data under the chain alleviated the storage pressure of the blockchain.By using the outsourcing supported multi-authority attribute-based encryption technology, the fine-grained access control of energy data was realized. Experimental simulation results show that in the proposed method, the blockchain network has availability, and outsourcing supported multi-authority attribute-based encryption technology has advantages in functionality and computing cost. Therefore, the proposed method can achieve fine-grained access control of energy data while protecting user privacy.