A fuzzy adaptive PID control-based capacity control method of an anesthesia machine. The method comprises: obtaining a corresponding initial voltage value according to a predetermined flow value, and inputting the voltage value as a current voltage value into a flow sensor obtaining a real-time flow value, and a difference value between the real-time flow value and the predetermined flow value, and inputting the two values into a fuzzy adaptive PID controller calculating and outputting a voltage value by regulating the proportional-control coefficient, integral-control coefficient, and derivative-control coefficient of the PID controller updating, by using the voltage value, the current voltage value and inputting the same into the flow sensor and repeating the process until the flow value outputted by the flow sensor satisfies requirements. By means of the method, an anesthesia machine can output a stable and accurate tidal volume in the situations of different predetermined values and different patients.
