Post-traumatic stress disorder (PTSD) is one of the common chronic diseases in psychiatry. It has a long course of disease which seriously affects patient’s life and work, and has a serious impact on social function. So far, the diagnosis of PTSD is limited to clinical symptom manifestations and physician experience, and no exact pathological substance basis is found, while the pathological substance basis is crucial for accurate diagnosis, selection of effective treatment methods, evaluation of treatment results, and assessment of disability. Head MRI is currently one of the most promising techniques to solve this problem. This paper reviews the progress in MRI research on brain structure changes in PTSD patients, in order to explore the possible future development directions.