The invention discloses a MIMO radar imaging method for improving the imaging quality of a large scene target. The method comprises that respective radiating antenna units of a radar array synchronously emit periodic and mutually orthogonal narrow pulse signals, and segment a two-dimensional imaging region jointly irradiated in the oblique viewing direction into a plurality of imaging strips withcertain widths; for each imaging stripe, the MIMO imaging radar array forms a new MIMO radar imaging configuration, establishes a new spatial spectrum model, and uses a MIMO radar imaging inversion algorithm to obtain the imaging result of each stripe; all imaged stripes are directly spliced to obtain the imaging result of the entire scene. The MIMO stripe division method and the independent stripe imaging method disclosed in the present invention solve a problem that a large number of transmit-receive array units and a powerful multi-channel data processing capability are required under a large-scene high-resolution MIMO radar imaging condition.