The present solution discloses methods and apparatuses for automatic processing of member management data in a blockchain. One example method includes storing, in a blockchain, a contract rule, wherein the contract rule includes a rule that is agreed upon by blockchain members and is used for determining registration conditions of registering users for joining a blockchain. Receiving a registration transaction message from a registering user based on the contract rule, wherein the registration transaction message includes identification information of at least one certification authority and a signature certificate of each of the certification authorities identified in the identification information. Verifying the at least one signature certificate based on the identification information by using public keys of the at least one certification authorities in a blockchain node. Finally, in response to determining that the at least one signature certificate are successfully verified, registering, as a new blockchain member, the registering user.