Abstract: In this paper, a motion compensation method based on Keystone transform is introduced to deal with the issue of multi-frame stepped Doppler frequency signal shift caused by mobile target. The stretching-drawing transform in time domain was employed to compensate the Doppler frequency shift. Moreover, two methods of parsing velocity ambiguity were studied: one is based on multi-channel Keystone transform and the other is based on binding information. Theoretical analysis and simulation results demonstrate that the compensation method could improve the velocity resolution and signal-to-noise efficiently. Also, the issues from target motion could be solved such as peak decrease, waveform divergence, etc.