Abstract: To address the challenges of data sharing latency, low multi-party collaboration efficiency, and difficult accountability traceability in the conventional quality acceptance of concealed works within underground structures, this paper proposes a multi-party collaborative quality acceptance model based on the Ethereum blockchain platform. The model delineates the roles and permissions of four stakeholders—namely, the contractor, the supervisor, the owner, and the government regulatory authority—via smart contracts, and establishes a closed-loop workflow encompassing acceptance application, approval, rectification, and confirmation. Leveraging the engineering context of Wuhan Metro Line 12, the simulated application of the proposed model to metro concealed works is investigated. Smart contracts were developed in Solidity and deployed on the Remix IDE platform for testing, verifying the real-time performance, immutability, and end-to-end traceability of on-chain data. The model enables a blockchain-based collaborative acceptance framework for concealed works involving all four parties. The event-driven data management ensures penetrative governance, providing technical support for judicial evidentiary preservation of engineering quality. Furthermore, the lightweight deployment scheme demonstrates high adaptability to the complex environments typical of underground engineering, thereby facilitating the practical adoption of blockchain technology in construction quality management.