Objective To analyze the imaging changes of CT ambient cistern in patients with traumatic brain injury before and after operation. Methods Eighty patients with traumatic brain injury treated in our hospital during May 2013 to May 2015 were selected as study subjects. All patients underwent brain CT scan. According to the change degree of ambient cistern, the subjects were divided into group A (14 cases), group B (25 cases), group C (31 cases) and group D (10 cases), and they were type I, II, III and IV respectively. The relationship between the compression degree of ambient cistern and the prognosis was compared, and the imaging characteristics were analyzed. Results The mortality rates in group A, group B, group C and group D were 0.00%, 23.81%, 53.85% and 86.67%, respectively, showing an increasing trend. The differences between any two groups were significant (P<0.05). There was no obvious compression of ambient cistern in 18 cases. Among patients without occlusion, there were 14 cases with good prognosis, 3 cases with moderate disability, 1 case with severe disability and none cases in persistent vegetative state or death. There was ambient cistern narrowing and mild compression in 21 cases. Among patients whose width of ambient cistern was 1-2mm, there were 12 cases with good prognosis, 2 cases with moderate disability, 1 case with severe disability, 1 cases in persistent vegetative state and 5 cases of death. Among 26 cases with moderate compression of ambient cistern and whose width of ambient cistern was < 1mm, there were 7 cases with good prognosis, 1 cases with moderate disability, 2 cases with severe disability, 2 cases in persistent vegetative state and 14 cases of death. Among 15 cases with severe compression of ambient cistern and complete occlusion, there was 1 cases with good prognosis, 1 cases in persistent vegetative state and 13 cases of death. Conclusion The severer compression of ambient cistern in patients with traumatic brain injury is, the worse prognosis is. Surgical treatment can reduce the compression of ambient cistern, achieving curative effect.