Intracranial aneurysm is a cystic bulge in the wall of intracranial artery and is the first cause of subretinal hemorrhage, ranking third among cerebrovascular accidents. The etiology is not well understood and is related to the congenital development of the arteries and the congenital lack of smooth muscle layer in the arterial wall. The onset of the disease is characterized by sudden onset, sudden headache, severe, stiff neck, nausea and vomiting, and severe and interesting disorders.