This paper proposes a Blockchain-based method for managing engineering contract changes to address the issues within engineering contract change management. First, it analyzes the prominent problems in engineering contract change management and explores the feasibility of integrating blockchain technology with engineering contract change management. Secondly, without altering the review or approval processes of engineering contract changes, it applies technologies such as distributed storage, merkle tree data structures, peer-to-peer networks, and smart contracts to explore the design ideas of an engineering contract change management information system encompassing the data layer, network layer, consensus layer, control and application layer. Finally, in conjunction with the engineering contract change management process of government investment projects, it presents an information system design scheme and architecture to provide new solutions for standardizing processes, tracing responsibilities, and enhancing supervision in engineering contract change management.