Aiming at the problems of security risk in vehicle communication and complex identity re-authentication when vehicles enter new infrastructure coverage in Vehicular Ad hoc NETwork （VANET）， a blockchain-based V2I （Vehicle-to-Infrastructure） fast handover authentication scheme in VANET was proposed. The decentralized， distributed and tamper-proof characteristics of blockchain were utilized to realize the storage and query of vehicle authentication information. Token mechanism was used to reduce the number of queries of blockchain， and simplify handover authentication process between Road Side Units （RSUs）. Because only the validity of token needed to be checked in subsequent authentication， rapid handover authentication of RSU was realized. Batch authentication was adopted to reduce the computation overhead and improve the efficiency of message authentication. In addition， the traceability and revocation of malicious vehicles was realized， and the anonymous identities of vehicles were updated in time to ensure the anonymity of vehicles. Compared with anonymous batch authentication scheme， authentication scheme with full aggregation， certificateless aggregate signature scheme， blockchain-based authentication scheme， the proposed scheme reduced the time consumption for message authentication by 51.1%， 77.45%， 77.56% and 76.01%. The experimental results show that proposed scheme can effectively reduce the computation overhead and communication overhead in VANET.