Traditional aquatic product traceability system has problems of tampering data, opaque links, and centralized management. To address the above problems, this paper designs master-slave multi-chain storage model to manage supply chain traceability information based on the analysis of the aquatic product supply chain and key information, so as to ensure the security of private data of enterprises and reduce the storage pressure of single-chain structure. At the same time, this paper designs an on-chain management and control smart contract to intelligently monitor all links of aquatic products from breeding to sales, and manage and control from the source. On this basis, this paper designs the traceability information management system of aquatic product blockchain based on master-slave multi-chain, implements the system based on Hyperledger Fabric, and proves the applicability of the system in combination with the actual application cases. Finally, this paper makes a comparative test with the blockchain single chain architecture. The results show that the storage model proposed in this paper carries out concurrent and hierarchical storage of traceability information, takes into account the two aspects of unnecessary sharing of private data and large single chain load, ensures the authenticity of traceability data, and achieves transparency in the traceability process.