Objective To investigate the application value of ultrasonic measurement of optic nerve sheath diameter (ONSD) in patients with craniocerebral trauma. Methods A total of 100 patients with craniocerebral trauma were selected as research subjects and randomly divided into control group and study group, with 50 patients in each group. Patients in the control group received invasive intracranial pressure (ICP) monitoring, while patients in the study group received invasive ICP monitoring combined with ultrasonic measurement of ONSD. Both groups were treated according to their actual conditions. The general information and treatment status of the two groups were observed, and the general information, ICP monitoring results, and ONSD ultrasonic measurement results of different ICP patients in the study group were compared. The correlation between ONSD and ICP in patients with craniocerebral trauma was analyzed, and the diagnostic efficacy of ONSD for ICP elevation in patients with craniocerebral trauma was also analyzed. Results At 28 days after treatment, the mean arterial pressure of the study group was higher than that of the control group, while the heart rate and respiratory rate were lower than those of the control group(P < 0.05). The mechanical ventilation time and ICU stay of the study group were shorter than those of the control group, the amount of mannitol used was less than that of the control group, and the ICP and 28-day mortality rate after treatment were lower than those of the control group (P < 0.05). Patients with ICP≥22 mmHg had higher ICP than those with ICP < 22 mmHg, and ONSD before and after the use of mannitol in different positions was greater than that in the ICP < 22 mmHg group (P < 0.05). There was a significant positive correlation between ONSD and ICP in patients with craniocerebral trauma (r=0.723, P < 0.001). The results of receiver operating characteristic curve analysis showed that the optimal cutoff value of ONSD for diagnosing ICP elevation was 5.25 mm, and the area under the curve was 0.879. Conclusion The combination of ICP monitoring and ultrasonic measurement of ONSD in the treatment of patients with craniocerebral trauma can effectively improve patients' vital signs, shorten the duration of mechanical ventilation and ICU stay, reduce the amount of mannitol used, and reduce the 28-day mortality rate. There is a significant positive correlation between ONSD and ICP in patients with craniocerebral trauma, and ONSD has a high diagnostic efficacy for ICP elevation.