In the digital age, data sharing faces challenges such as privacy risks, permission management issues, and compliance concerns. To address these, this paper proposes BDSN (Blockchain-based Data Sharing Network), a multilayered infrastructure designed for secure and efficient data sharing. BDSN comprises six layers—device, blockchain, identity, data, service, and application networks—with characteristics of openness, standardization, security, and flexibility. By integrating blockchain technology, it enables identity authentication, data lifecycle management, and trusted service execution, aiming to become a core infrastructure for the digital society under the concept of “co-construction, co-governance, and sharing”.