This three-volume set, CCIS 2637-2639, constitutes the refereed proceedings of the 7th International Conference on Blockchain, Artificial Intelligence, and Trustworthy Systems, BlockSys 2025, held in Zhuhai, China, during May 30-31, 2025. The 110 full papers included in this book were carefully reviewed and selected from 254 submissions. They were organized in topical sections as follows: Part I: Blockchain Security & Attack Mitigation; Identity Authentication & Data Privacy; Blockchain Applications & Industry Solutions. Part II: Deep Learning Architectures & Optimization; Computer Vision & Medical Image Analysis; Natural Language Processing & Multimodal Learning; Reinforcement Learning & Edge Computing Systems. part III: Blockchain & Smart Contract Trustworthiness; Federated Learning & Edge Computing ; Industrial & IoT System Reliability.