Digital subtract angiography (DSA) is one of the most important methods for diagnosing cerebrovascular disease, which can visually determine the degree and extent of stenosis and observe the collateral circulation; the lesions shown are more intuitive and superior to other imaging methods such as ultrasound, transcranial Doppler, magnetic resonance angiography (MR angiography, MRA), spiral CT angiography (CTA), etc. in determining the source and number of diseased supply arteries, the direction of draining veins, and the degree of stenosis of diseased vessels. It is superior to other imaging examinations, such as ultrasound, transcranial Doppler, magnetic resonance angiography (MR angiography, MRA), spiral CT angiography (CT angiography, CTA), magnetic resonance venous angiography (MRV), CT perfusion imaging, etc. At present, DSA is still regarded as the “gold standard” for diagnosing cerebrovascular lesions. DSA is still regarded as the “gold standard” for the diagnosis of cerebrovascular lesions. Its application in the clinic is wide, and all diseases related to cerebrovascular disease can be applied to this diagnostic method. In recent years, the development and clinical application of three-dimensional DSA (3D-DSA) has significantly improved the diagnostic accuracy of cerebrovascular diseases, especially aneurysms, and the 3D technology provides richer information for clinical treatment by imaging the morphology of the aneurysm itself and its multi-angle with surrounding vessels. (A) Common indications and contraindications of DSA Indications: (1) cerebrovascular disease: ischemic or hemorrhagic cerebrovascular disease, which can search for the cause and determine the treatment plan; (2) preoperative understanding of blood supply for rich vascular tumors of the head and face; (3) observation of the relationship between the blood supply of intracranial occupying lesions and the neighboring vessels; (4) review of the head, face and intracranial vascular diseases after treatment; (5) clarification of vascular lesions and surrounding anatomical relationship. Contraindications: (1) contrast allergy; (2) allergy to contrast equipment; (3) severe bleeding tendency or bleeding disorders; (4) severe cardiac, hepatic and renal insufficiency; (5) severe systemic infection or local infection at the puncture site; (6) uncontrolled hypertension; (7) concurrent brain herniation or other life-threatening conditions. (ii) DSA method Preoperative preparation Communicate and educate the patient, understand and exclude serious cardiac and renal disorders and bleeding disorders, routine blood tests, transfusion series, blood glucose, lipids, platelets, and clotting time. The perineum was prepared with bilateral inguinal skin preparation, iodine allergy test, fasting 4 h before surgery, and sodium phenobarbital 0.1 g intramuscular injection 30 min before surgery. DSA is to inject the contrast agent into the bilateral common carotid artery and vertebrobasilar artery with a high-pressure syringe at a certain rate and within a certain period of time to visualize the blood vessels, and to take rapid and continuous multi-angle pictures. Usually, the Seldings technique is used, in which a 4F or 5F catheter sheath is placed through the puncture of one femoral artery, systemic heparinization is performed, and the aorta, bilateral common carotid arteries, internal and subclavian carotid arteries, and bilateral vertebral arteries are imaged with the introduction of 4F or 5F pigtail catheters and single-curved catheters, respectively. After extraction of the sheath, compression is applied for 15-20 min to stop bleeding, 1 kg sandbag is applied for 6 h, and the affected limb is braked for 24 h. The commonly used contrast agent is iohexol or Uvexan. （The incidence of DSA complications is low, <3%; the common manifestations are: bleeding at the puncture site, vasospasm, thrombosis or embolism, etc. The incidence of DSA complications is low, <3%.