In life, there are often elderly people who accidentally injured their head and did not pay attention to it because there was no obvious discomfort, but after one month (or so), dizziness and headache, vomiting, severe weakness of limbs, slurred speech, slow reaction or even coma, etc. This requires alerting to the possibility of chronic subdural hematoma. Chronic subdural hematoma refers to the accumulation of blood from intracranial hemorrhage in the subdural cavity and the appearance of symptoms more than three weeks after the injury, which is mostly seen in trauma. There is no uniform understanding of the source and pathogenesis of hematoma. At present, the mainstream view supports the “hematoma envelope hemorrhage, local coagulation disorder theory”, but which factors play the main role and the role between them need to be further studied. Clinical manifestations: 1. symptoms of increased intracranial pressure: headache, vomiting, optic nerve papillary edema. Infants and children often have convulsions, vomiting, feeding difficulties, bulging fontanelle and increased head circumference. 2, mental disorders; dementia, apathy, memory loss, disorientation and mental retardation, etc. 3, focal brain symptoms: hemiplegia, numbness, aphasia and focal epilepsy, etc. Diagnosis: CT or MRI examination of the head is a more ideal diagnostic method, with the advantages of simplicity, safety, and the ability to show the location, size and number of hematoma within a short time of CT performance of chronic subdural hematoma. When the hematoma shown by CT and MRI is isointense, enhanced scanning or MR examination can be performed. Treatment: 1. Bone flap craniotomy for chronic subdural hematoma removal: it is an early treatment, mainly for chronic subdural hematoma with thicker envelope or calcification. The surgical method is to lift the bone flap and see the bruised and thickened dura mater. A small hole is incised to slowly drain the accumulated blood, and after the intracranial pressure is slightly lowered, the dura and the outer membrane of the hematoma immediately beneath it are flap-shaped and turned over together to reduce blood leakage. The inner membrane of the hematoma and the arachnoid membrane are easy to separate and should be excised, but they should not be pulled by force to avoid tearing the border of the inner and outer membrane, which is prone to bleeding and can be cut at 0.5 cm near the edge. After surgery, the bleeding should be properly stopped, the dura mater and scalp layers should be sutured in layers, and the hematoma cavity should be drained by tube for 3-5 days. Bilateral hematomas should be staged and operated on laterally. This method is less commonly used because of the large trauma. 2.Drilling or cone hole irrigation and drainage: according to the site and size of the hematoma, two holes (one high and one low) are selected before and after. Under local anesthesia, the cranial borehole is first drilled in the anterior part or the cranial cone hole is used to enter the cavity of the hematoma, and then the old blood and brown blood clots flow out, and then the silicone tube or No. 8 urinary catheter is carefully placed into the cystic cavity, and the length cannot exceed the radius of the hematoma cavity to further drain the liquid hematoma. In the same way, the lower part (posterior part) was re-drilled or tapered to drain the cyst and a catheter was placed, followed by repeated flushing with saline gently through both catheters until the flushing fluid became clear. After the operation, the two drains were separately drained out of the skull through separate scalp punctures and connected to sterile sealed drainage bags. The high drainage tube is drained and the low drainage tube is drained and removed in about 3-5 days. Recently, it has been reported that simple cone cranial irrigation can be used, which can be done directly at the bedside via scalp cone cranial, draining the old blood and rinsing with saline until it is clear, repeating the cone cranial irrigation every 3-4 days, usually about 2-4 times, until the brain is released from compression and the midline structure is reset under CT monitoring. 3. Minimally invasive puncture and drainage: The patient identifies the target point (i.e., the thickest level of the hematoma) under CT and selects a 20-25 mm long YL-1 type needle, and the puncture point should avoid the middle meningeal artery and its branches. Routine preoperative preparation, skin preparation, local anesthesia with Y L-1 needle drill one intracranial hematoma crushing puncture needle connected to electric drill, drill through the skull, let the hematoma fluid flow naturally, when not dripping after repeated flushing with 5 ml of saline equivalent basic clear open drainage; with clot inserted into the hematoma crusher with 5 ml of saline equivalent repeated flushing, and inject urokinase 1-2 million U; clamp the lateral tube 4h after release open drainage. Once a day; drainage for 3-5 d, bilateral hematoma retention needle for 4-7 d, review CT to remove the puncture needle and suture a needle. Minimally invasive hematoma puncture has been routinely performed in our department because of its simple operation method, usually the whole operation is completed within 20 minutes, the injury is slight, no cerebrospinal fluid leakage; it is not easy to cause intracranial infection; its effect is very satisfactory; it is the best method for treating chronic subdural hematoma at present.