A data transmission method and central controller for a distributed antenna system and a distributed antenna system. The system includes a central controller and multiple wireless transceiver units. The method includes that wireless transceiver units measure the power of the pilot reference signals received from user terminals and forward this power rate to a central controller; the central controller selects a set of wireless transceiver units for transmitting data to the terminal according to the pilot reference signal power rates of the terminals forwarded by the multiple wireless transceiver units; the central controller performs data processing according to said set of wireless transceiver units; the central controller distributes the processed data to the wireless transceiver units in said set of wireless transceiver units, and the wireless transceiver units in said set perform the downlink data transmission.