A single audio interface signal switching circuit and a single audio interface switching device are provided by the embodiments of the present disclosure, which sets only one single audio interface and uses a working mode switching module to control a driver chip to generate different drive signals, in order to control working states of an audio signal output module, a time code input module, and a time code output module electrically connected with the driver chip. Since there is only one audio interface, and a working mode of the single audio interface switching device is controlled by the working mode switching module, so that a volume of the single audio interface switching device is reduced.