A method for blockchain-based time stamping for digital signature is disclosed. The method includes two participants: a signer who signs a message, a verifier who verifies the message. In the method, the signer obtains hash values of a certain number of latest confirmed blocks in blockchain, binds these hash values and the message together to be a new message. The signer then generates a signature of the new message and inserts identification data of this signature and the new message into a transaction of blockchain. This method ensures that the generation time of the signature is prior to the generation time of the block which contains the signature and, at the same time, is after the generation time of the blocks whose hash values are included in the signature, which produces an accurate time interval for the digital signature.