Objective To investigate the application value of transcranial Doppler (TCD) in patients with poor-grade intracranial aneurysm (Hunt-Hess III to V).Methods Hemodynamic parameters of the middle cerebral artery were monitored for 56 patients with poor-grade intracranial aneurysm at different time windows, including mean flow velocity (V_m) and peak flow velocity (V_p). The patients were randomly divided into Vm group with 28 patients (the dose of nimodipine was adjusted according to the clinical manifestations and V_m) and Vp group with 28 patients (the dose of nimodipine was adjusted according to the clinical manifestations and V_p). Each group was further divided into the elderly group and the middle-aged group according to whether the age was ≥ 60 years. At 3 months after subarachnoid hemorrhage (SAH), Glasgow Outcome Scale (GOS) score was used to evaluate patients' prognosis, and a comparative analysis was performed between the two groups.Results In the Vm group, there were 14 patients with poor prognosis and 14 patients with good prognosis, and in the Vp group, there were 12 patients with poor prognosis and 16 patients with good prognosis; there was no significant difference in prognosis between the two groups (P>0.05). In the middle-aged Vm group, there were 6 patients with poor prognosis and 11 patients with good prognosis, and in the middle-aged V_p group, there were 9 patients with poor prognosis and 4 patients with good prognosis; there was no significant difference in prognosis between the two groups (P>0.05). In the elderly V_m group, there were 8 patients with poor prognosis and 3 patients with good prognosis, and in the elderly V_p group, there were 3 patients with poor prognosis and 9 patients with good prognosis; the elderly V_p group had a significantly better prognosis than the elderly V_m group (P<0.05).Conclusions TCD can achieve the noninvasive and real-time monitoring of hemodynamic changes in patients with poor-grade intracranial aneurysm, so as to provide a theoretical basis for individualized treatment.