This book constitutes the refereed proceedings of the Second Conference on 2025 International Conference on Blockchain and Web3.0 Technology Innovation and Application Exchange, BWTAC 2025, held in Chengdu, China, during November 7–9, 2025.The 41 full papers and 3 short papers included in this book were carefully reviewed and selected from 98 submissions. They were organized in topical sections as follows: Protocols, Security, and Smart Contracts; Data, Governance, and Applications; and Scalability, Cross-Chain, and Ecosystems.