Objective To investigate the relationship between CT findings of diffuse axonal injury (DAI) and the severity and prognosis. Methods A total of 104 patients with DAI who were admitted to the department of neurosurgery of the hospital from February 2017 to February 2018 were divided into the simple interpeduncular cistern hemorrhage group (n=37), the simple midline hemorrhage group (n=19), interpeduncular cistern hemorrhage with midline hemorrhage group (n=19) and control group (n=29). The Glasgow Coma Scale (GCS) score, coma time, brainstem damage rate and poor prognosis rate were compared between groups. The correlation between interpeduncular cistern hemorrhage and brainstem damage was analyzed by Spearman correlation coefficient analysis. Results Compared with the control group, the GCS score was higher, coma time was longer, the proportion of brainstem damage was larger and the poor prognosis rate was higher in the simple interpeduncular cistern hemorrhage, the midline hemorrhage group or interpeduncular cistern hemorrhage with midline hemorrhage group (P<0.05). Compared with the simple midline hemorrhage group, the GCS score was higher, coma time was longer, the proportion of brainstem damage was larger and the poor prognosis rate was higher in the simple interpeduncular cistern hemorrhage (P<0.05). Spearman correlation analysis showed that there was a significant positive correlation between interpeduncular cistern hemorrhage and brainstem damage (r=0.768, P<0.05). Conclusion CT signs of interpeduncular cistern hemorrhage and midline hemorrhage of patients with DAI can reflect the poor prognosis. There is an obvious correlation between interpeduncular cistern hemorrhage and brainstem damage.