With the rapid development of the electricity market, businesses such as market regulation and market dispute resolution are facing significant challenges. The reliable storage of business data is the key foundation for solving these problems, blockchain technology provides us with new idea. In this paper, we comprehensively considered the characteristics of both electricity market and blockchain technology, then designed the Electricity Market Alliance Chain and implemented a blockchain-based data storage system for electricity market. The system achieved more than 1.3 million market data on-chain storage, and realized the full life cycle traceability mechanism of transaction and settlement business. Based on the data on the blockchain, Green Electricity Usage Certificates are generated and issued for market members by smart contracts, which provide an important reference for carbon emission verification in a transparent way. At last, we designed a set of experiments to test the performance of the system, and the results prove that it can fully meet performance requirements.