Abstract: At present, electronic information systems on the market mostly use mobile phone number verification, or other associated account binding registration methods in the user registration function design. Although this registration and login method is convenient and fast, personal information is also collected by platforms, which increases the risk of personal information leakage. In order to protect the security of personal information used in user registration and relieve the various troubles caused by the leakage of personal information, this paper proposes a user registration and login method based on blockchain technology. By constructing the alliance chain, the blockchain technology was integrated with the registration and login system to ensure that users could still use their mobile phone numbers to register in the alliance chain without revealing personal information to software application vendors and hide user login application record. After the registration was successful, users could log in to all systems on the alliance chain. The alliance chain system issued a unique identification number to the application node in the chain, and users used the account to post the transaction to apply for the login node, generated a zero-knowledge scope certificate during the application login process to hides the login record.