A mobile communication data transmission method for a cell having one base station and more than one relay station involves switching the relay stations between at least two operating modes of signaling transmission under the control of the base station. A system transmits mobile communication data in a cell having one base station and more than one relay station. When transmitting an uplink signaling or a downlink signaling, the relay stations switch between at least two operating modes under the control of the base station. By using the method, network, relay station, and base station, data transmission in multiple modes can be achieved, so as to achieve a flexible relay scheme.