Intravenous anesthetics are non-volatile general anesthetics, which are mainly administered by intravenous injection. Compared with inhaled anesthetics, the depth of anesthesia is not easy to master and the discharge is slow. Generally, it is only suitable for small operations with short time and low requirements for analgesia. The single use range is not wide, and it is mostly used for induction of inhalation anesthesia and compound general anesthesia in clinic.