With the development of electricity supply, electricity marketing data continue to grow. Traditional centralized data storage modes have been unable to meet the security and efficiency requirements of power business data storage. To address the issues, this paper proposes a multi-level encrypted electricity marketing data storage architecture based on blockchain. The storage architecture uses the blockchain as the underlying technical support and combines with distributed storage to provide highly stable, secure and reliable power data storage scheme. At the same time, a multi-level encryption mechanism is proposed on the basis of the blockchain. This mechanism supports step-by-step encryption and verification of power data on-chain and power data transmission processes, which further guarantees the security of power data storage. The proposed storage mechanism is compared with the centralized storage mechanism by creating a distributed storage facility. The experimental results show that the proposed storage mechanism has more advantages in terms of system latency, response time, and throughput than traditional storage mechanisms, indicating that the proposed storage mechanism is reasonable and feasible and has good application prospects.