The invention relates to a micro-blog multi-signature method based on a chain block. The method comprises the following steps: 1, performing user registration to obtain a pair of public key and private key and an address for transaction and generated by the private key; 2, creating multi-signature addresses by m users by using the addresses obtained in step S1; 3, creating micro-blog sending transaction, and inserting to-be-sent information in the transaction by using an OP-RETURN operator, wherein the OP-RETURN operator is operated by the multi-signature addresses created in step S2, the multi-signature addresses support the authority of n of m; and 4, performing digital signature on the micro-blog transaction by the users onsite in turns, and broadcasting the micro-blog transaction after at least n signatures are obtained, and permanently recording the micro-blog transaction in the block chain after the success of the transaction. The micro-blog multi-signature method has the advantages of not worrying about tampering and deletion of the micro-blog, generating no advertising push, and having high security and high information credibility, etc.