Objective To investigate the value of 3.0T high-resolution magnetic resonance imaging (HR-MRI) in the diagnosis of plaque in the vessel wall of middle cerebral artery stenosis. Methods 41 patients with middle cerebral artery stenosis admitted from January 2018 to January 2020 were selected for the study, all of whom underwent HR-MRI, and the diagnostic results of digital subtraction angiography (DSA) were used as the gold standard to compare HR-MRI findings in middle cerebral artery stenosis with DSA diagnostic results. The NWI and responsible plaque heights of non-ischemic stroke and ischemic stroke patients at 6 months, 12 months, 18 months and 24 months after discharge were compared. Results 41 patients were found to have stenosis in 49 middle cerebral arteries by DSA, including 33 cases of unilateral stenosis and 8 cases of bilateral stenosis. The diagnostic accuracy, specificity and sensitivity of HR-MRI in middle cerebral artery stenosis were 93.90% (77/82), 90.91% (30/33), 95.92% (47/49). There was no obvious distinction in NWI and responsible plaque height at 6, 12, 18 and 24 months after discharge in patients with ischemic stroke (P > 0.05). When comparing NWI and responsible plaque height at corresponding time points after discharge in non-ischemic stroke patients, the distinctions were not obvious (P > 0.05). Compared with the group of ischemic stroke, the non-ischemic stroke group NWI was lower at corresponding time points (P < 0.05). No obvious distinctions were found between the group of ischemic stroke and the group of non-ischemic stroke in terms of responsible plaque height at 6, 12, 18 and 24 months after discharge (P > 0.05). Conclusion HR-MRI has highly valuable applications in the diagnosis of plaque in the wall of middle cerebral artery stenosis, which can accurately determine the stenosis of middle cerebral artery. Through HR-MRI, it was found that the plaque in the wall of patients with middle cerebral artery stenosis was stable after conventional treatment.