The embodiment of the invention discloses a communication
mode switching method and device. The method comprises the following steps of: receiving a sending request; detecting whether the
radio frequency signal strength of a downlink channel meets a first threshold; when the
radio frequency signal strength is greater than the first threshold, judging that a
relay station is in a working state, and keeping a relaying mode to finish the sending request; when the
radio frequency signal strength is less than the first threshold, judging that the
relay station is in an abnormal state, and switching to an offline mode to finish the sending request, wherein the offline mode specifically is to perform sending after regulating the sending frequency to be the receiving frequency of the downlink channel. Obviously, whether the
relay station is in the abnormal state is judged by detecting whether the
signal strength of the downlink channel meets the preset threshold, sequentially, the working mode is switched between the relaying mode and the offline mode in a targeted manner, thus, when the relay station is in the abnormal state, the receiving frequency of the downlink channel is used as the sending frequency for sending signals, so that other mobile stations are guaranteed to be capable of receiving the sent signals, and the rate of call lost is lowered.