Authentication is an important way to exam and identify electronic evidence, and it's also a prerequisite for judging the evidence capability of electronic evidence. As the king of evidence in the age of network information, electronic evidence is being used in an increasingly wide range of judicial practices. However, electronic evidence is virtual and is easily tampered with, which makes the examination of the completeness and authenticity of electronic evidence more difficult. How to ensure that electronic evidence will not be tampered with or deleted in evidence circulation is the important and difficult points in authentication. Because distributed ledger, asymmetric cryptographic algorithm, timestamp and other technologies are embedded in blockchain storage, the electronic evidence can't be tampered with and deleted after entering the blockchain, and the work of authentication can be accomplished. With the increasingly widespread application of blockchain storage technology in social life and work areas, its combination with electronic evidence derives the electronic evidence of blockchain, a new type of electronic evidence. Some scholars take the blockchain storage of electronic evidence as electronic evidence of blockchain, and discuss the authentication of such electronic evidence. But the two are different, with the latter a type of electronic evidence and the former a way of authentication. In addition, they are differing in the time of evidence preservation, degree of authenticity and identity, factual relevance, value function and so on. Thus, from the perspective of the function of blockchain storage, if the electronic evidence has been authenticated, it doesn't need to be authenticated again. If we authenticate it again, the legitimacy and necessity of implementing the blockchain storage of electronic evidence in judicial practice will be greatly reduced. As a way of authentication, blockchain storage is differ from electronic evidence of blockchain in terms of authenticity and identity. This misconception taking blockchain storage as electronic evidence of blockchain and authenticating it stems mainly from theoretical misunderstanding of the blockchain storage of electronic evidence. The generation of electronic evidence of blockchain depends on the generation and development of blockchain technology, and has the unique characteristics of blockchain technology. The generation of electronic evidence which is storaged by blockchain aren't depend on the blockchain technology. The blockchain storage platform is the tool for preserving and fixing the electronic evidence, which will not generate new evidence to prove the facts of a case. It undertakes the same functions as traditional authentication methods, which makes authentication about electronic evidence move from systematic presumption of authenticity to self-attestation of authenticity by technology, and promotes the diversified development of electronic evidence authentication. What's more, blockchain storage of electronic evidence can only provide guarantee for the formal authenticity of electronic evidence entering the blockchain and the opposite party also can challenge the authenticity.