A bandwidth sharing method and device based on SDN control of terminal cell are disclosed. The bandwidth sharing method includes: determining, by a SDN controller, whether a trigger request for bandwidth sharing is received; upon receipt of the trigger request, selecting at least one second terminal cell for providing bandwidth sharing to the first terminal cell; controlling the first terminal cell and the at least one second terminal cell to jointly process the target service. The trigger request indicates a need of bandwidth sharing of a first terminal cell from other terminal cells when processing a target service on a backhaul link, and a bandwidth requirement of the target service equals to or exceeds a first predetermined threshold. The SDN controlled bandwidth-sharing scheme may ensure the application of a wireless backhaul sharing mechanism between T-SCs, thereby achieving flexible configuration of bandwidth resources on the backhaul link.