In recent years, due to the development of intelligent connected devices, vehicle CAN-FD bus security is facing huge problems and challenges. Firstly, this paper introduces the data vertical structure, characteristics and advantages of CAN-FD bus in detail. Secondly, this paper analyzes the network vulnerability of CAN-FD bus and proposes a possible attack model against the vulnerability. Finally, on the basis of in-depth understanding of the existing defense models, this paper proposes the detection method of vehicle CAN-FD bus data and encryption authentication technology. It provides the possibility to ensure the information security of CAN-FD bus without affecting the normal running of vehicles.