A flow calibration method and system for an anesthesia machine flow sensor, the method comprising the following steps: gradually increasing the flow rates of a plurality of anesthesia machines, and when preset conditions are satisfied, acquiring the voltage values of the flow sensors (S101) calculating the average voltage value of the plurality of sampling points of each anesthesia machine, and obtaining, by means of the average voltage value of the plurality of sampling points of each anesthesia machine, the default voltage curve of the flow sensors (S102) dividing the default voltage curve into 3 sections, and selecting in the 3 sections 4 calibration points and acquiring the voltage value of each calibration point (S103) calculating the voltage difference, for each calibration point, between the acquired voltage and the default voltage curve, and according to the voltage difference, accurately calibrating the flow of the anesthesia machine (S104). According to the method, by means of determining the calibration points within a segmented range and according to the voltage differences between the default voltage curve and the calibration points, the flows of other acquisition points can be determined, reducing the level of complexity of the calibration process and also ensuring calibration accuracy.
