”Subarachnoid hemorrhage” is one of the acute and critical neurosurgical conditions. Its name is somewhat specialized and differs from the general brain hemorrhage in that the hemorrhage is diffused on the surface of the brain rather than in the brain tissue. Treatment includes two aspects: 1) treatment of the bleeding, depending on the situation, most of them are treated by conservative infusion; 2) examination and treatment of the cause of bleeding. Intracranial aneurysms are the most common cause of subarachnoid hemorrhage. If an aneurysm is present and not treated, repeated bleeding may aggravate the condition and even cause disability and death. An aneurysm is a localized sac-like protrusion on a larger diameter vessel in the skull that ruptures with a weak tip. Aneurysms can only be treated by surgical intervention, and the conventional methods are: 1. endovascular intervention; 2. craniotomy.