Abstract: The traditional centralized trading model in the energy field is affected by its centralized processing method. There are many problems such as high maintenance costs and inability to guarantee openness and transparency, which restrict the willingness of trading entities to enter the market. To this end, this paper proposed and developed a weakly centralized multi-energy trading system. First, from the blockchain, a distributed, tamper-resistant decentralized technology, based on the Ethereum platform, the placing energy trading mechanism was written into smart contracts. The administrator role could add or delete energy types that allow transactions, and users could initiate real-time transactions and information. Inquiry, a transaction matching model based on the market supply and demand relationship for smart contracts was discussed. Next, the contract was deployed in the Ethereum private chain, and the ether.js interface was used to interact with the client to realize the visualization of smart contracts and satisfy user transactions with the query requirements, while the user information was stored in the database, the administrator realized the management of energy and users without interference in the transaction process. Finally, the reliability and profitability of the platform's functions were verified according to a calculation example. This weakly centralized energy trading system provided a new model and solution for the application of blockchain technology in the energy field.