Embodiments of the present invention provide a data offloading method and a base station. The method includes: sending, by a master base station, a first request message to a mobility management control node, where the first request message includes an address of a local gateway of a secondary base station, and the first request message is used to request to perform data offloading at the local gateway of the secondary base station; receiving, by the master base station, a first response message that is sent by the mobility management control node according to the first request message, where the first response message includes a first related identifier (ID) of the local gateway of the secondary base station, and the first related ID is used to indicate a first bearer according to which data offloading is performed at the local gateway of the secondary base station.