An oxygen battery calibration system (100), an anesthesia machine comprising the oxygen battery calibration system (100), and a calibration method applied to the oxygen battery calibration system (100), wherein the oxygen battery calibration system (100) comprises: a breathing circuit (110), comprising an inspiratory branch (111), an expiratory branch (112), an absorption tank branch (113), an inspiratory one-way valve (114), a connection pipeline (116) and an expiratory one-way valve (115), wherein the inspiratory branch (111) and the expiratory branch (112) communicate via a connection pipeline (116)； an oxygen battery (120) connected to the inspiratory branch (111) and a joint is located at a rear end of the inspiratory one-way valve (114)； and a calibration management unit, the calibration management unit controlling a calibration gas to enter the inspiratory branch (111), and flow out through the oxygen battery (120), the connection pipeline (116) and the expiratory one-way valve (115), and the calibration management unit performing oxygen concentration calibration according to the calibration gas flowing through the oxygen battery (120). When the oxygen battery (120) is being calibrated, it is not necessary to unplug the connection pipeline (116), and the calibration gas can flow from the inspiratory branch (111) to the expiratory branch (112) without entering the absorption tank branch (113), so that automatic calibration of the oxygen battery (120) is realized, which ensures the reliability of the operation of the oxygen battery (120), and improves the convenience of calibration of the oxygen battery (120).
