Abstract: The rise of the new four modernizations of automobiles has accelerated the speed of the automotive electronic control unit (ECU) to mass production, and the increasing code volume of ECU has also put forward higher requirements for the efficiency of ECU software upgrade in the OEM. Aimed at the problem of low efficiency of updating procedures by traditional refreshing tools in OEMs, a multi- channel synchronous refreshing scheme based on UDS diagnostic protocol is proposed. With LabVIEW as the development environment, the program adopted CAN- Ethernet networking to achieve communication and data interaction between the upper and lower units. By configuring different IP addresses and port numbers, ECUs could be uniquely identified in the network. The experimental results show that the system can complete the online upgrade of software for multiple ECUs and meets the design needs regarding refresh success rate, synchronization, and reliability, significantly improving the time performance and efficiency of ECU refreshing compared with the traditional refreshing tools.