An adaptive threshold segmentation method, which is based on inhomogeneous illumination images, has been proposed in view of such flaws as highlight areas, shaded areas, and anomalous marginal areas caused by photographed images under the condition of inhomogeneous illumination. It seeks to realize the separation of the target and its background with the aid of the local threshold value and dynamic fine adjustment value of the images. The experimental results verify that the method can achieve a rapid and effective segmentation of the target and its background, thus extracting the target information efficiently.