Blockchain technology has the functions of distributed data storage and embedded editable smart contracts, and can provide a flexible, safe and transparent settlement environment and trust foundation for power transaction settlement. Firstly, this paper briefly describes the technical characteristics of blockchain and analyzes the feasibility of transaction settlement application; Then, the application design of private chain, alliance and smart contract is carried out in combination with the power transaction settlement scenario. Finally, the possible problems in the application of power transaction settlement based on blockchain technology are analyzed to provide reference and guidance for practical application.