The etiology of intracranial aneurysm: congenital aneurysm, atherosclerotic aneurysm and traumatic aneurysm, mostly infected aneurysm in children. Clinical manifestations: Before the aneurysm ruptures, most patients have no clinical symptoms, but some patients may have symptoms and signs due to the large size and compression of adjacent nerves and brain tissue. If the aneurysm ruptures, it may lead to subarachnoid hemorrhage or intracerebral hematoma. Sudden and severe headache, nausea, vomiting and psychiatric symptoms may be seen. On examination, hemiparesis, cerebral neurological deficits and meningeal irritation are seen. Lumbar puncture may reveal a bloody cerebrospinal fluid. Diagnosis: CT can detect intracranial hemorrhage and CT angiography can detect most intracranial aneurysms early, but the gold standard is still whole brain angiography to confirm the diagnosis. Treatment of intracranial aneurysm: Non-surgical treatment, surgical treatment and endovascular embolization are the main treatments. The purpose of non-surgical treatment is to prevent or delay rebleeding of the aneurysm, relieve cerebral vasospasm, relieve cerebral edema, and protect brain function. To create conditions for surgery or other treatments. It is suitable for those who are too old and frail and have serious organ disease to tolerate surgery; aneurysm at grade 5 or above. Non-surgical treatment may include: absolute bed rest for more than 4 weeks to keep the patient quiet; appropriate lowering of blood pressure to reduce the impact of cerebral blood flow on the arterial wall; application of anti-fibrinolytic enzyme drugs; application of dehydrating drugs to combat cerebral edema and reduce intracranial pressure; and relief of cerebral vasospasm. A. Craniotomy treatment: The purpose of surgical treatment of aneurysm is to prevent bleeding or rebleeding of aneurysm. At present, with the development of neuro-microsurgery technology, the success rate of aneurysm surgery has improved significantly, and the surgical mortality rate has decreased to 1~2%. There are direct and indirect surgical treatment methods: direct surgery, the purpose of which is to externally cut off the traffic between the aneurysm and the aneurysm-carrying artery and keep the aneurysm-carrying vessel open. This includes aneurysm neck clamping, aneurysm foxing, and aneurysm reinforcement, with aneurysm neck clamping being the most common and effective. The specific procedure depends on the size of the aneurysm, the condition of the aneurysm neck, and the relationship between the aneurysm and the surrounding arteries. The purpose of indirect surgery is to ligate the common or internal carotid artery on the side of the aneurysm in stages so that the distal blood pressure decreases, reducing the impact of blood flow on the aneurysm wall and reducing the flow rate into the aneurysm cavity. Before ligation, internal carotid artery compression test, i.e. Matas test, should be done to promote the establishment of collateral circulation, and the cerebral hemisphere on the diseased side can get blood supply from collateral circulation, which is now used sparingly. B. Endovascular embolization: Endovascular embolization is performed by inserting a microcatheter into the aneurysm cavity under digital subtraction X-ray machine fluoroscopy, and then pushing a microspring coil (GDC) through the microcatheter into the aneurysm cavity to occlude the aneurysm from the inside and promote thrombosis within the aneurysm, while the aneurysm-carrying artery remains open. With the development of microinvasive neurosurgery, endovascular embolization of aneurysms has been gradually promoted as one of the main treatment methods for cerebrovascular diseases. This technique is safe, with little damage, reliable embolization of aneurysms and rapid patient recovery. In Europe and the United States and other developed countries, intravascular embolization has become the main method for treating intracranial aneurysms and has the tendency to gradually replace craniotomy.