A wireless communications system includes a baseband processing unit (BBU), an optical multiplexer, M (greater than or equal to 2) first optical transceivers, and a wireless radio frequency apparatus, where the M first optical transceivers are provided between the BBU and the optical multiplexer, and operating wavelengths of the M first optical transceivers are different from each other. The wireless radio frequency apparatus includes M remote radio units (RRUs), M second optical transceivers separately corresponding to the M first optical transceivers, and at least one optical splitter, where the M second optical transceivers are separately connected to the M RRUs, and an operating wavelength of a first optical transceiver matches an operating wavelength of a corresponding second optical transceiver. The M second optical transceivers are connected to a same optical fiber by the optical splitter, and the optical fiber is connected to the optical multiplexer and the optical splitter.