Abstract: When applying to a high-precision and wide-beam airborne SAR, the frequency domain imaging algorithms are incapable of accurate Motion Compensation (MoCo), while the precise time domain approaches have the drawback of heavy computation burden. A novel imaging algorithm is proposed to figure out the problem, which combined the frequency domain methods and the time domain ones through a perturbation operation to the two-dimensional spectrum of the signal. The algorithm improves the MoCo precision with the computation efficiency being ameliorated as well, thus balancing the accuracy and efficiency when implements on the high-precision and wide-beam airborne SAR. The results of the simulation and real data are used to validate the effectiveness of the proposed algorithm in application to the high-precision and wide-beam airborne SAR.