Brain hemangioma, also known as intracranial aneurysm, its causes are as follows: first, genetic factors, brain hemangioma exists a certain hereditary chances, genetic factors will cause the patient’s intracranial arterial vascular wall of the middle layer of the elastic fiber loss, resulting in thinning of the vascular wall, the impact of the blood flow will be formed under the effect of intracranial aneurysm. Secondly, high blood pressure, long-term high blood pressure will lead to the patient’s intracranial artery degeneration, vitellogenic changes, the brittleness of blood vessels increases, in the case of elevated blood pressure, blood flow impact increases the easy formation of cystic protrusion, resulting in the formation of aneurysms. Third, medical factors, if the arterial vessel wall is inadvertently damaged during the surgery, it will cause the vessel wall to be damaged and thinned, and aneurysm will also be formed. Fourth, craniocerebral trauma, for craniocerebral trauma, especially skull base fracture, the broken bone fragments of the fracture will puncture the blood vessel wall of the skull base, resulting in damage to the blood vessel wall and formation of aneurysm. Fifth, infection, infection will also violate the arterial blood vessel wall in the skull, causing damage to the elastic fibers in the blood vessel wall, thus triggering an aneurysm.