In the era of digital economy, the development of digital supply chain has brought many transaction disputes and transaction security problems. Establishing a traceability system has become an effective means to solve these problems. However, traditional traceability technology has problems such as opaque information and easy data tampering, which requires a more secure and reliable way to trace digital supply chain. Therefore, this paper proposes a digital supply chain traceability method based on blockchain technology and using Pailler algorithm, Merkle Tree and smart contract, aiming to improve the security and reliability of transactions. This method was developed on the FISCO BCOS platform and was evaluated for performance and visual effects, proving its effectiveness and feasibility.