Objective To investigate the effect of endovascular embolization combined with fasudil hydrochloride in the treatment of cerebral aneurysms and its influence on immune function and serum levels of matrix metalloproteinase-9 （MMP-9） and caspase-3.Methods A total of 74 patients with cerebral aneurysms who were admitted to our hospital from January 2015 to January 2021 were enrolled and randomly divided into control group and observation group， with 37 patients in each group. The patients in the control group were given endovascular embolization and conventional treatment， and those in the observation group were given fasudil hydrochloride in addition to the treatment in the control group. The two groups were compared in terms of transcranial Doppler findings， immune function， serum levels of MMP-9 and caspase-3， and postoperative complications.Results After treatment， both groups had significant increases in the blood flow velocity of the anterior， middle， and posterior cerebral arteries （P <0.05）， and the observation group had a significantly higher blood flow velocity than the control group （P <0.05）. After treatment， both groups had significant increases in the levels of IgA and IgM （P <0.05） and a significant reduction in the level of IgG （P <0.05）， and the observation had significantly higher levels of IgA， IgM， and IgG than the control group （P <0.05）. After treatment， both groups had significant reductions in the levels of MMP-9 and caspase-3 （P <0.05）， and the observation group had significantly lower levels of MMP-9 and caspase-3 than the control group （P <0.05）. The observation group had a significantly lower incidence rate of complications than the control group （13.51% vs 37.84%， P <0.05）. The observation group had a slightly higher incidence rate of adverse reactions than the control group （P >0.05）.Conclusions In the treatment of cerebral aneurysms， endovascular embolization combined with fasudil hydrochloride shows good safety and can effectively prevent cerebral vasospasm， improve immune function， and reduce the levels of MMP-9 and caspase-3.