To explore the critical care treatment and clinical outcome of patients with severe aneurysmal subarachnoid hemorrhage (SaSAH), and to provide clinical evidence for the treatment of patients with SaSAH. 160 patients with SaSAH of Hunt and Hess (H&H) grade III or above in the neurosurgical critical care unit at ourospital between June 2016 and June 2018 were enrolled in this study. Patients were treated with brain protective bundle based on step-wised protocol under multimodal monitoring and followed up for 3 months. The incidence of various clinical complications and the clinical prognosis after discharge were statistically analyzed. Furthermore, it carried on the correlation analysis to the risk factors and the prognosis. In 160 patients with SaSAH, 127 patients had responsible aneurysms located in the anterior circulation, and the other 33 patients were located in the posterior circulation. 70 patients (43.8%) underwent transcranial clipping, 81 patients (50.6%) underwent endovascular embolization and 9 patients (5.6%) did not intervene. Patients with IV and V grades of Glasgow Outcome Scale (GOS) were considered good recovery, and those with grade I, II and III were poor prognosis. The 30-day good prognosis rate was 41.3% (66/160) and the poor prognosis rate was 58.7% (94/160). Multivariate logistic regression analysis showed that the Hunt & Hess classification correlated well with prognosis (OR: 4.367,95% CI, 2.254-8.460, P < 0.001). The clinical prognosis of patients with SaSAH is still poor. In particular, under the critical care of neurosurgery, the application of brain protective bundle based on step-wised protocol under multimodal monitoring might improve the clinical prognosis of patients with SaSAH.