The present invention relates to a data transmission method and a base station, the method includes: determining, by a base station according to channel state information CSI, a transmission path for forwarding first data to a first terminal, where if the base station determines that the first data needs to be forwarded by at least one small cell to the first terminal, the transmission path includes a path from the base station to a small cell and a path from the small cell to the first terminal; and sending, by the base station according to the transmission path, a first data frame to the first terminal via the at least one small cell. In the present invention, a macro base station performs centralized scheduling, and performs unified encapsulation according to a scheduled transmission path, thereby effectively simplifying processing by a forwarding node and reducing a delay.