A wide-band antenna multiplexing method and device of an unmanned aerial vehicle (UAV) are disclosed. The method comprises: by a wide-band antenna, receiving an external signal and sending the received external signal to a first power divider; by the first power divider, dividing the external signal received from the wide-band antenna into multi-way sub-signals, and sending each sub-signal respectively to a receiving filter of a plurality of receiving filters, each of which is connected to the first power divider and corresponds to a functional modules of the UAV respectively; and by each respective receiving filter, performing filtering processing on the received sub-signal, obtaining a signal corresponding to the working frequency band of each respective functional module of the UAV, and sending the signal corresponding to the working frequency band of each respective functional module of the UAV to a corresponding functional module.