Embodiments of the present invention relate to a method and device for determining RRU. The method includes: a BBU obtains interference strength information of a terminal, where the interference strength information includes a downlink mode of the terminal. The method further includes: if demodulation is performed by using a dedicated reference signal (DRS) in the downlink mode, the BBU performs resource scheduling on the terminal by using a second RRU, where the second RRU is selected by the BBU from multiple first RRUs that serve the terminal; or if demodulation is performed without using a DRS in the downlink mode, the BBU performs resource scheduling on the terminal by using a third RRU, where the third RRU is determined by the BBU according to any one of an uplink signal strength value of the terminal, a downlink quality value of the terminal, or an uplink quality value of the terminal.