Credit Link is a plugin that serves as a credit card based on blockchain and DID distributed identity authentication technology. It can be issued on any blockchain (consortium chain, public chain, or private chain) and provides user-based distributed information storage credentials for the operated blockchain network. The credential information is anonymously registered on-chain in NFT format. Users can present their credential information ownership to merchants in need of authentication through the Credit Link client app on their phones. Credit Link automatically matches the on-chain anonymous information with user information consistency, triggering user authorization, event authenticity verification, or points inquiry and deduction tasks.