[Objective] To summarize the experiences of three-dimensional computed tomography angiography (3D-CTA) in the simulation of intracranial aneurysm clipping surgery, search the data of individuation 3D-CTA imitation image.[Methods] A total of 69 patients were underwent aneurysm clipping surgery during 2006.1 2011.12.The angle of the line (the craniotomy point to aneurysm neck) with horizontal plane and sagittal plane were detected before surgery, which was used to guide the individuation operative approachs via adjusting 3D-CTA image on CT work station.Result] The three-dimensional imitation images before surgery were completely in accordance with the scene during surgery.All of the aneurysms were clipped successfully in euthyphoria situation.69 patients were followed up for 3 48 months, the prognosis was evaluated by GOS score.57 patients were good recovery, 8 patients were moderate disability, 2 patients were severe disability and 2 patients were dead.[Conclusion] According to angle (the line of craniotomy point to aneurysm neck with horizontal plane and sagittal plane) to adjust 3D-CTA image can acquire vivid three-dimensional image about the aneurysm before surgery, which can assist in improving surgery security and reducing the difficulty.