The principle of local anesthesia is that because the trauma sensation is transmitted to the brain center through the nerve, the nerve generates action potential through the inward flow of sodium ions in the process of transmitting electrical signals, and after blocking sodium ions, no action potential will be generated and the pain signal will not be transmitted to the brain center. In contrast, local anesthetic drugs are sodium channel blockers, and local anesthesia is performed by infiltrating anesthetic drugs around the surgical incision, which can block the signal transmission of peripheral nerves around the incision and achieve the purpose of anesthesia.