Hemianesthesia is a common form of anesthesia used in clinical practice, mainly for lower extremity and lower abdominal surgery. Semi-anesthesia is called intradural anesthesia, and intradural anesthesia is an invasive, blind operation that may result in a number of accidents and complications. Firstly, there is a risk of epidural bleeding, headache after dural puncture, possible damage to nerve roots and spinal cord, and neurotoxicity of local anesthetics can lead to limb numbness and even paraplegia. Secondly, total spinal anesthesia can lead to cardiac and respiratory arrest, and the epidural tube may be broken and knotted in the body during extraction. In addition, intraspinal anesthesia can lead to headache with intracranial low pressure, and can also lead to back pain.