A first network device determines configuration information of a target flexible Ethernet (FlexE) group that needs to be adjusted, and adjusts the target FlexE group synchronously with a second network device based on the configuration information of the target FlexE group. The second network device communicates with the first network device through a physical layer link in the target FlexE group. The configuration information of the target FlexE group includes a backup FlexE group number and a backup FlexE map of the target FlexE group, and the backup FlexE map includes information about the physical layer link in the target FlexE group. The first network device and the second network device perform synchronous adjustment. In this way, embodiments of this application provide a management solution for losslessly and dynamically adjusting a FlexE group, to avoid impact on a service and implement FlexE group adjustment in various scenarios.