Abstract: For the purpose of obtaining high-resolution image of airborne moving target, this paper proposes a technical approach based on MIMO radar. Firstly, the basic principle and scheme of MIMO radar are analyzed. Then MIMO radar imaging model is founded. The relationship between MIMO radar multi-channel data and the spatial spectrum of target is derived. The high azimuth resolution of MIMO radar array is proved through analysis of spatial spectral region of support. Finally, simulations are performed and the results show that MIMO radar array can improve the azimuth resolution by several times compared with real aperture array that has the same receiving array as MIMO radar.