Provided are a service bearer configuration method and DEVICE, which relate to the field of communications and solve the problem in the prior art that a service data bearer method for serving a UE isnot established and updated for a 5G L2Relay network, and the requirements of multiple paths and multiple hops cannot be met. The method is applied to a first CU, and comprises the following steps: configuring a mapping relationship between a flow and a DRB; sending the mapping relationship to a second CU, wherein the first CU is a CU for providing service for the terminal, and the second CU is aCU for providing service for the IAB. According to the scheme provided by the invention, the service bearer configuration of the L2relay is realized; a complete data service channel can be establishedwhen the 5G terminal accesses the wireless station, and the whole L2relay architecture can more completely meet the multi-path and multi-hop service transmission requirements, so that the service experience of a user is improved, and the network transmission efficiency is improved.