Post-traumatic stress disorder (PTSD) is a kind of psychological disorder caused by unusual threatening or catastrophic events, and it is one of the urgent public health events in the 21^st century, which deserves more attention. Exploration of the underlying brain mechanisms of PTSD can provide theoretical basis for the early intervention, psychological nursing and follow-up treatment of PTSD. Current studies have analyzed PTSD brain functional magnetic resonance imaging at resting state and task state. The results showed that the amygdala response was enhanced in PTSD patients, and their hippocampal volume was reduced with decreased response of anterior cingulate cortex and medial prefrontal cortex. Future studies should attach greater importance to the selection of control group, with special focus on the presence of comorbidity.