The invention discloses a measuring method of an airborne single-station passive positioning system on a measure target radiation wavelength. The measuring method comprises the following steps: making an airborne single-station passive probing platform do constant motion along a straight line; firstly, using the receiving front end to process received probing signals; then, sending the received probing signals into a digital signal processing unit; sending signal frequency values obtained through regular detection under the control of a synchronous clock into a memory; and calling the latest three frequency values from the memory by the data processing unit in a mode of automatic or manual commands under the triggering effect of the regular synchronous clock to measure the wavelength of the measured signals. The invention can accurately estimate and obtain the wavelength of the measure target radiation signals through the simple frequency measuring technology, and the measuring methodcan be applied to the execution of long distance positioning measuring tasks. However, an aerial measuring platform which has simple equipment and can not be supported by a ground measuring system can also be applicable to the monitoring management of aerial radio signals.