Most cerebral aneurysms have spontaneous subarachnoid space as the first symptom, accounting for about 80% to 90%. There may be specific neurological signs, such as internal carotid artery-posterior communicating artery aneurysm hemorrhage, there may be ipsilateral actinic nerve palsy; if the hemorrhage is large enough to form a huge hematoma, it may endanger the patient’s life. Preoperative DSA examination can clarify the diagnosis. Treatment may include open aneurysm clamping and endovascular intervention. This patient, male, 52 years old, was admitted to hospital with “headache for 1 day”. Preoperative CT examination showed subarachnoid hemorrhage, and CTA and DSA examination showed anterior communicating artery aneurysm. Aneurysm clamping was performed under general anesthesia. He recovered well after surgery.