Lumbar puncture, which is a lumbar puncture to extract cerebrospinal fluid for pathogenic examination, is mainly used for diagnosis of diseases and also for treatment of diseases. It is mainly used clinically for the diagnosis of patients with encephalitis and meningitis. If subarachnoid hemorrhage is considered, lumbar puncture to extract cerebrospinal fluid for fluid release therapy is mainly used for the treatment of the disease. The preferred site for lumbar puncture is the 4th and 5th lumbar intervertebral spaces, and the 3rd and 4th lumbar intervertebral spaces may also be selected. If the 4th and 5th lumbar intervertebral spaces are selected, the tip of the needle should be slightly tilted at an angle of about 45 degrees between the head and the spine. If the 3rd and 4th intervertebral spaces of the lumbar spine are selected, the needle should be inserted vertically. During the retention of cerebrospinal fluid, the flow rate must be slow to prevent the occurrence of brain herniation when the patient’s intracranial pressure is increased. Also, after the lumbar puncture is completed, the patient must be instructed to lie flat with the pillow removed for 4-6 hours.