Aiming at the problem of communication interruption caused by line break in CAN bus network of construction machinery and tram,a new cost-effective synchronous double redundant CAN bus design is proposed.The synchronization of the traditional dual redundant CAN bus is improved.At the same time,the problem of redundant line time difference caused by error retransmission of CAN bus is solved by the design.The test results show that the real-time performance and security of CAN bus redundant lines is improved by this design.There is no data loss in the case of single line short circuit and open circuit.It is further verified that it has great value to the stable operation of construction machinery and tram.