This paper describes a modified MIMO-SAR ω-k algorithm integrating with motion compensation to achieve high resolution. Firstly, a model of motion error for airborne MIMO-SAR system was established. Then improved Stolt-mapping was proposed to separate Range Cell Migration Correction (RCMC) and azimuth focus, and the motion error was corrected by two steps of compensation. Finally, sub-bands were combined into a whole band in spatial-frequency domain to obtain high range resolution. Simulation examples are provided to verify the validity of the method.