The invention discloses a proportional valve control method which is used for controlling the ventilation flow of a proportional valve V1 in a valve interface circuit. In the proportional valve control method, a processor emits a preset digital value voltage; an analog-digital conversion circuit converts the digital value voltage into an analogue value voltage; a reference voltage regulation circuit regulates the analogue value voltage into a reference voltage; a driving circuit controls the opening degree of the proportional valve V1 according to the reference voltage; a current detection circuit detects whether the working state of the proportional valve V1 is normal or not; if the working state of the proportional valve is normal, a detection result is output to the processor, and the processor controls the ventilation flow of the proportional valve V1; and if the working state of the proportional valve is abnormal, a protection circuit cuts off the driving circuit by force. The invention also provides a proportional valve control circuit. The proportional valve control method and the circuit thereof dynamically regulate the flow, effectively control the ventilation flow and improve the reliability and the security of the machine.