Abstract: Aiming at the problem of range nonstationarity in clutter spectrum of end-fire array airborne radar, a method of clutter suppression based on sparse recovery with range ambiguity is proposed. Firstly, the underdetermined equation of clutter echo data is established by sparse recovery theory, the space-time spectrum distribution of clutter is obtained by focal underdetermined system solver algorithm, and the clutter covariance matrix of each range gate is reconstructed. Then, the farthest detectable range unit is used as the reference unit to compensate the clutter data and constrain the target. Finally, the space-time adaptive clutter suppression processing is carried out based on the compensated data. Compared with the traditional nonstationary clutter spectrum compensation method for end-fire array airborne radar with range ambiguity, the clutter covariance matrix estimation accuracy of this method is high, and the clutter suppression performance is better. Theoretical analysis and simulation results verify the effectiveness of the proposed method.