Post-traumatic stress disorder（ PTSD） is a severe mental illness characterized by recurrent trauma re-experiencing， active avoidance of trauma-related stimuli， negative alterations in cognition and mood， and hyperarousal symptoms. In recent years， neuroimaging studies of trauma-exposed individuals have revealed that the pathological mechanisms of PTSD are closely associated with functional abnormalities in three brain networks： the default mode network， the salience network， and the central executive network. By reviewing and analyzing advances in functional magnetic resonance imaging（ fMRI） studies based on the triple network model， this paper further elucidates the roles of the three networks in the onset and progression of PTSD， aiming to provide reference for future research in related fields.