Abstract: A blockchain-based-distributed sharing, secure, transparent, efficient and convenient intelligent access control system is designed to address the identity recognition issues in the access management of various persons with different permissions concerning the specific areas of offshore wind farms. The means such as ID card, fingerprint, and facial recognition are independently identified and registered at each node according to their specific power production system’s "two tickets" process management, power production operation duty record management, and other rules and regulations. And then based on ID card or QR code as the carrier, the identifiers are put out based on password technology, and the identification outcomes are published on the blockchains for certificate sharing and traceability. During access control recognition, multiple modes such as ID card, QR code,or biometric features are supported, and verification and comparison are conducted based upon the identity data on the blockchains. Ultimately, the goal of "identification in one place, available for all places" and "interoperability and mutual learning" in multiple sea-land regions.