Objective To investigate the clinical value of magnetic resonance imaging (MRI) in the evaluation of cerebral small vascular injury of patients with type 2 diabetes mellitus. Methods A total of 120 cases of patients admitted to department of neurology in hospital from March 2017 to March 2018 were selected and divided into 2 types, diabetes mellitus type 2 group (60 cases) and non-diabetes group (60 cases) according to the presence or absence of type 2 diabetes mellitus. Two groups were given MRI scan. The occurrence and types of acute infarction, intracerebral microbleeds, lacunar infarction and leukoaraiosis were compared between the two groups. Results Compared with nondiabetes group, the incidence rates of acute infarction and small vessel infarction were higher in type 2 diabetes mellitus group while the incidence rate of large vessel infarction was lower(P<0.05). The degrees of lacunar infarction and leukoaraiosis in type 2 diabetes mellitus group were higher than those in non-diabetes group (P<0.05). Conclusion MRI can show the occurrence and types of acute infarction, and the degrees of intracerebral microbleeds, lacunar infarction and leukoaraiosis. And it has diagnostic value for the assessment of cerebral small vascular injury in patients with type 2 diabetes mellitus.