Spontaneous subarachnoid hemorrhage (SAH) is caused by rupture of intracranial aneurysm in 80% of cases, and ranks third after cerebral thrombosis and hypertensive cerebral hemorrhage in cerebrovascular accidents. The disease occurs in middle-aged and elderly people aged 40 to 60 years old, and is rare in adolescents. Intracranial aneurysm is not a tumor, but an abnormal bulge in the wall of intracranial artery, mostly cystic bulge, mostly not more than 1cm, and small aneurysm of 2-3mm is also common. Brain aneurysms are mostly found at the bifurcation of the arteries at the base of the brain. They are more common in the anterior communicating artery and posterior communicating artery. Most intracranial aneurysms are usually asymptomatic, but once they rupture, subarachnoid hemorrhage occurs, which can be manifested as headache, nausea and vomiting, and impaired consciousness depending on the amount of hemorrhage, and in severe cases, coma and death soon after the onset. According to statistics, after the first rupture of an aneurysm, the mortality rate is as high as 30-40%, half of which die within 48 hours after the onset of the disease; about one-third of the patients will remain disabled after treatment. Most aneurysms rupture and the rupture is closed by clotting to temporarily stop bleeding, but as the clot around the aneurysm rupture dissolves, the aneurysm may rupture and bleed again. If the aneurysm is not treated, rebleeding will occur in approximately 20% of patients within 2 weeks of the first bleed, and the mortality rate for rebleeding can be as high as 60%. Therefore, timely diagnosis and treatment of aneurysms is critical to saving patients with spontaneous subarachnoid hemorrhage. Although there is some variation in the timing and measures of treatment depending on the amount of bleeding and the patient’s post-onset symptoms, the current consensus is to diagnose and treat aneurysms as early as possible. A small number of patients with aneurysms present with precursor symptoms of hemorrhage, more commonly posterior communicating aneurysms, which may present with actinic nerve palsy, manifested by unilateral eyelid ptosis, pupil dilatation, inability to internalize, superior and inferior vision, and loss of direct and indirect light responses. There are also precursor symptoms manifested as mild migraine and orbital pain. These patients should be given high priority and treated promptly in an effort to treat the aneurysm before bleeding occurs. The majority of patients with spontaneous subarachnoid hemorrhage present to the emergency neurology department with a very high positive rate of CT confirmation. Once the diagnosis of spontaneous subarachnoid hemorrhage is confirmed, definitive examination of the aneurysm should be performed as soon as possible. Three-dimensional CT angiography (CTA) can detect most of the aneurysms; DSA cerebral angiography is the gold standard for intracranial aneurysm examination, which is very important to determine the exact location, morphology, internal diameter, number, vasospasm and treatment plan of aneurysm. Cerebral angiography is mostly performed via femoral artery puncture and cannulation, and contrast is injected into the blood supplying arteries of the brain along with rapid dynamic radiography, which provides clear images of cerebral vessels. Once spontaneous subarachnoid hemorrhage is diagnosed as a ruptured aneurysm, it is recommended that the aneurysm be treated as soon as the patient’s general condition allows. There are two surgical options for the treatment of aneurysms: craniotomy clamping and interventional therapy. Craniotomy clamping is the traditional treatment method, which is to expose the aneurysm with microsurgical technique after craniotomy and to clamp the aneurysm at the neck of the aneurysm with aneurysm clamps, which has definite effect, but the surgery is more traumatic and requires higher systemic condition of the patient. Interventional treatment is based on cerebral angiography using an arterial route to deliver a microcatheter into the aneurysm cavity and filling the cavity with a special embolic material to prevent bleeding, which is less invasive but more costly to implant. These two methods are used for most aneurysms.