The invention discloses a small cell base station system, and related devices and data processing methods, and the small cell base station system includes an extended small cell base station and at least one distributed component, where the extended small cell base station includes a network protocol processing module, an upper layer protocol processing module, a physical layer protocol processing module, a first baseband data processing module, and a first transceiver module; and the distributed component includes a second baseband data processing module and a second transceiver module, where in the downlink, the first baseband data processing module separates downlink baseband data into at least two branches, performs a data alignment operation on the at least two branches of downlink baseband data, sends one of the branches to the first transceiver module, and Ethernet encapsulates and then sends the remaining branches to the second transceiver module through the second baseband data processing module of the distributed component, thus extending a coverage area of the small cell base station system.