Objective To explore the clinical value of optic nerve sheath diameter (ONSD) by ultrasonic detection in the diagnosis and treatment of patients with acute increased intracranial pressure (ICP). Methods A total of 180 patients with acute increased ICP in the hospital were enrolled between March 2020 and March 2023. ONSD and ICP were collected before surgery (T0), after anesthesia (T1), at the beginning of surgery (T2), immediately after surgery (T3) and immediately after awaking (T4). The relationship between ONSD and ICP at different time points was analyzed. According to scores of Glasgow Outcome Scale (GOS), they were divided into good prognosis group (157 cases) and poor prognosis group (23 cases). ONSD in the two groups was compared before surgery and immediately after surgery. The correlation between ONSD and GOS score was analyzed. The predictive value of ONSD for prognosis in patients with perioperative acute increased ICH was analyzed by receiver operating characteristic (ROC) curves. Results From T0-T2, there was no significant change in ONSD or ICP, but which were significantly decreased from T3-T4 (P<0.05). The results of Pearson correlation analysis showed that ONSD was positively correlated with ICP from T0-T4 (P<0.05). After surgery, levels of ONSD and ICP were decreased in both groups, which were lower in good prognosis group than poor prognosis group (P<0.05). The results of Spearman correlation analysis showed that ONSD and ICP were negatively correlated with GOS score immediately after surgery (P<0.05). The results of ROC curves analysis showed that AUC values of ONSD and ICP for predicting poor prognosis immediately after surgery were 0.886 and 0.782, which were of good predictive value (P<0.05). Conclusion ONSD by ultrasonic detection can effectively evaluate ICP in patients with acute increased ICP, which also has certain prognostic value.