The invention discloses a method for realizing reconfiguration in dual
connectivity, a master eNB (MeNB), and a secondary eNB (SeNB). In a process of transferring a user plane bearer of UE to a target SeNB of the same MeNB from a source SeNB, a user plane interface for providing uplink data service and downlink data service is established between the source SeNB and the target SeNB; and in a reconfiguration process, the target SeNB forwards an uplink RLC data PDU to the source SeNB, and the source SeNB distributes a downlink
PDCP data PDU to the target SeNB and maintains
data transmission with the UE until the reconfiguration is successful. In a process of establishing the connection with the target SeNB by the UE, the user plane interface for providing uplink / downlink data service for the UE is established between the source SeNB and the target SeNB so that the problem that when the UE performs uplink and downlink synchronization with the target SeNB and establishes connection, the UE fails to perform
data transmission with a network side at the layer of a micro
base station or a low-power node is solved, rapid reduction of the data
throughput of the user plane is avoided, and the user experience of the UE during reconfiguration of the user plane is guaranteed.