Major depressive disorder （MDD） is one of the most commonwith high disability， and its pathogenesis is still unclear. As a noninvasive neuroimaging technique， MRI can reveal the brain function of patients with severe depression. Compared with healthy controls， the functional changes of frontal lobe， temporal lobe， hippocampus， cingulate gyrus， basal ganglia， cerebellum and other brain areas in patients with severe depression may indicate the pathophysiological abnormalities of MDD. This article reviews the latest research results of multimodal MRI， including diffusion tensor imaging （DTI）， diffusion kurtosis imaging （DKI）， magnetic resonance spectroscopy （MRS）， functional MRI （fMRI）， neurite directional dispersion and density imaging （noddi） in MDD， in order to have a better understanding of its neurobiological mechanism.