The reflection of colors and surfaces of common targets, lead to errors in the measurement of visibility based on the image method. This study aims to investigate the problem of inaccurate visibility detection. Through analysis of the error of visibility measurement caused by the reflection of the blackboard surface of an artificial target, the design method of improving the structure of the target board is proposed, so as to improve the accuracy of atmospheric visibility measurement by the image method. The experimental results show that the new target board designed by this method can greatly improve the measurement accuracy of the intrinsic apparent brightness ratio, which can increase 18.4% in the fairing environment and closer to –1 in the side light environment. Therefore, when the side light is selected for the image method visibility measurement, more accurate visibility results can be obtained.