There are four processes for head angiography: routine preoperative examination, anesthesia, puncture injection, and fluoroscopy. The details are analyzed as follows: 1. Routine preoperative examination: before head angiography, routine preoperative examinations such as urine routine, blood routine, coagulation time, etc., are usually performed to ensure that the angiography is smooth. 2. Anesthesia: general anesthesia is required if the patient is relatively young and unconscious. If the patient is more conscious, can cooperate with the examination and has the ability of independent behavior, usually only local infiltration anesthesia is needed. 3. Puncture and injection: Generally, the vertebral artery, internal and external carotid artery, common carotid artery and other arteries will be selected as the puncture point, and then a catheter will be placed to inject iodine contrast medium. 4. Fluoroscopy: The iodine contrast agent will usually show a clear image of the blood vessel under X-ray fluoroscopy, which is convenient for the doctor to check the flow of iodine contrast agent in the blood vessel, so as to determine the status of the blood vessel.