An anesthesia machine is a device that delivers anesthetic drugs into the patient's alveoli through a mechanical circuit, forming a partial pressure of anesthetic gas that diffuses into the bloodstream and directly inhibits the central nervous system, resulting in the effect of general anesthesia. The anesthesia machine belongs to a semi open anesthesia device. It mainly consists of anesthesia evaporator, flow meter, folding bellows ventilator, respiratory circuit (including suction and exhalation one-way valves and manual airbags), corrugated pipeline and other components.