A method for a central unit handover in which a UE is handed over from a source central unit, CU, to a target central unit, wherein a first distributed unit, DU, is shared by the source CU and the target CU and the UE is served by the first DU before and after the CU handover, the method comprising: receiving, by the first DU, a first bearer setup request that is about a first service and that is sent by the target CU, wherein the first bearer setup request comprises a first service identifier; determining, by the first DU based on the first service identifier, whether a service resource needs to be allocated to the first service, wherein the determining, by the first DU based on the first service identifier, whether a service resource needs to be allocated to the first service comprises: if a service identifier set comprises the first service identifier, and a service indicated by any service identifier in the service identifier set is a service being executed by the first DU, determining, by the first DU, that the first DU is serving the first service and that no service resource needs to be additionally allocated to the first service, and to continue to use a service resource serving the first service; and if the service identifier set does not comprise the first service identifier, determining, by the first DU, that the service resource needs to be allocated to the first service; and sending, by the first DU, a first bearer setup response to the target CU, wherein the first bearer setup response comprises information used to indicate whether the service resource needs to be allocated to the first service. receiving, by the first DU, a first bearer setup request that is about a first service and that is sent by the target CU, wherein the first bearer setup request comprises a first service identifier; determining, by the first DU based on the first service identifier, whether a service resource needs to be allocated to the first service, wherein the determining, by the first DU based on the first service identifier, whether a service resource needs to be allocated to the first service comprises: if a service identifier set comprises the first service identifier, and a service indicated by any service identifier in the service identifier set is a service being executed by the first DU, determining, by the first DU, that the first DU is serving the first service and that no service resource needs to be additionally allocated to the first service, and to continue to use a service resource serving the first service; and if the service identifier set does not comprise the first service identifier, determining, by the first DU, that the service resource needs to be allocated to the first service; and if a service identifier set comprises the first service identifier, and a service indicated by any service identifier in the service identifier set is a service being executed by the first DU, determining, by the first DU, that the first DU is serving the first service and that no service resource needs to be additionally allocated to the first service, and to continue to use a service resource serving the first service; and if the service identifier set does not comprise the first service identifier, determining, by the first DU, that the service resource needs to be allocated to the first service; and sending, by the first DU, a first bearer setup response to the target CU, wherein the first bearer setup response comprises information used to indicate whether the service resource needs to be allocated to the first service.