The invention discloses a bistatic airborne radar adaptive clutter spectrum compensation method based on improved OMP. OMP is orthogonal matching pursuit for short. By aiming at a bistatic airborne radar clutter distance non-stationarity problem, Doppler frequencies of main lobe clutters are estimated, and by adopting the improved OMP, the spatial frequencies of the main lobe clutters are acquired, and therefore main lobe clutters of different distance units are compensated respectively. According to a simulation experiment result, after adaptive compensation, the bistatic airborne radar clutter distance non-stationarity is improved, and by adopting 3DT, an improvement factor is improved by about 6Db in a main lobe clutter region. The bistatic airborne radar adaptive clutter spectrum compensation method has advantages of good adaptive compensation effect, small calculation quantity, and easy project implementation.