Objective To investigate whether precise surgical planning based on multimodal image fusion and 3D reconstruction technology can reduce adverse events during clipping in patients suffered from ruptured intracranial anterior circulation aneurysm with severe subarachnoid or intracephalic hematoma. Methods Using 3D Slicer 4.10.2，multimodal image fusion and 3D reconstruction were performed basing on preoperative CT and CTA images of 23 patients with high⁃grade Hunt⁃Hess grade anterior circulation ruptured aneurysms. According to personalized surgical plan its guiding to craniotomy aneurysm clipping，we compare the consistency of preoperative three⁃dimensional imaging results with the actual observation during operation，and evaluate its pros and cons for reducing intraoperative adverse events. Results Accurately guided by the preoperative simulated the head position and craniotomy，we can significantly reduce the adjustment of the patient′s head position during the operation and the secondary grinding off the sphenoid ridge due to poor exposure of the sylvian fissure. According to the intraoperative observation，the sensitivities of the aneurysm neck shape，the poor parts of the transition zone of the aneurysm′s neck to body，and the small perforating vessels beside the neck displayed in the 3D images were 90%，50%，and 75%，respectively，and the specificities were 100%，100%，and 75%，respectively. Kappa coefficients were 0.701， 0.623 and 0.732，respectively. The sensitivity and the specificity of preoperative simulated clipping for the actual intraoperative clipping was 100% and 25% respectively，and the Kappa coefficient was 0.355. Conclusion The precise plan based on preoperative multimodal image fusion and 3D reconstruction technology can effectively help the surgeon to accurately individualize the craniotomy clipping of ruptured anterior circulation aneurysm with severe subarachnoid hemorrhage or intracephalic hematoma and reduce the incidence of intraoperative adverse events.