An auto-iris control method, including setting a target luminance value of an auto iris; collecting an image at a current moment and calculating a luminance value of the image collected at the current moment; comparing the target luminance value with the luminance value of the image collected at the current moment; comparing an absolute value of the luminance difference at the current moment with a preset luminance difference threshold, determining a status of the auto iris at the current moment, and using a corresponding proportional-integral-derivative (PID) algorithm to calculate a direct current control voltage at the current moment; and adjusting an action of the auto iris according to the calculated direct current control voltage.