Lumbar puncture is an operation in which a puncture needle is inserted into the subarachnoid space to collect cerebrospinal fluid or to administer drugs to the subarachnoid space. First, the patient is placed in a lateral position with the head low, knees bent, and thighs as close to the stomach as possible in a curled position. The puncture site is located in the lumbar 3 and 4 interspace or 2 and 3 interspace, and generally the iliac spine is connected to the lumbar 3 and 4 interspace and the lumbar 4 vertebral body. After positioning, local disinfection and sterile towels were applied, and the puncture site was locally anesthetized with 2% lidocaine. Afterwards, the lumbar puncture needle is inserted perpendicular to the skin and passes through the skin, subcutaneous, supraspinous ligament, interspinous ligament, ligamentum flavum, dura mater, and arachnoid in turn. The first breakthrough sensation is the breakthrough sensation of piercing the ligamentum flavum, and the second is the breakthrough sensation of piercing the dura mater. After the needle penetrates the dura mater, the cerebrospinal fluid can be seen flowing out when the needle core is removed, and the cerebrospinal fluid can be collected or medication can be given in the subarachnoid space through the lumbar puncture needle.