Objective To explore the efficacy of conservative and surgical treatment for severe post-traumatic acute diffuse brain swelling (PADBS).Methods Forty-four patients, who were admitted to the Department of Neurosurgery in our hospital for severe PADBS from January 2016 to December 2019, were divided into surgery group and conservative treatment group. The Glasgow Coma Scale (GCS) score on admission, head CT examination results, Glasgow Outcome Scale (GOS) score at six months after injury, and length of hospital stay were statistically analyzed.Results There were no significant differences in age, sex, GCS score on admission, and GOS score at six months after injury between the two groups (P>0.05). However, the surgery group had a significantly longer length of hospital stay than the conservative treatment group (P<0.05).Conclusions Patients with severe PADBS can choose conservative treatment under close clinical observation if they do not have pupil changes or reduction in the GCS score.