The invention discloses a medium-frequency signal analogy method in airborne Doppler navigation radar, comprising the following steps: expanding quadrature modulation technology into single side band modulation; using an integrated circuit and automatic program control; and under the combined action of airborne Doppler navigation radar control signal and reference signal, simulating to generate medium-frequency spectrum signals at four different wave beam directions of the radar, which have different frequencies and are superposed with corresponding noise, equivalent to echo signals received when an airplane is in actual flight at different speeds and different heights. Moreover, the method can carry out accurate step-by-step attenuation on the generated medium-frequency signal, so as to meet the requirement on airborne Doppler navigation radar test. The invention has novel design, high integration level, simple structure, low cost and convenient use, and can effectively improve the test efficiency of the airborne Doppler navigation radar.