CAN bus, in the automobile industry, has developed various electronic control systems for the requirements of safety, comfort, convenience, low pollution and low cost. Because the data types used in communication between these systems and the requirements for reliability are different, many cases are composed of multiple buses, and the number of wire harnesses has also increased. In order to meet the needs of "reducing the number of wire harnesses" and "carrying out high-speed communication of a large amount of data through multiple LANs", the German Electric Company 1986 Bosch developed the CAN communication protocol for automobiles. Since then, CAN has been standardized by ISO/KOOC-0//KOOC-0/898 and ISO/KOOC-0//KOOC-0/5/KOOC-0/9, and has become the standard protocol of European automobile networks. The high performance and high reliability of CAN have been recognized and widely used in industrial automation, ships, medical equipment, industrial equipment and other fields. Fieldbus is one of the hot spots in the field of automation technology development, and it is called computer local area network in the field of automation. Its appearance provides strong technical support for distributed control system to realize real-time and reliable data communication between nodes.