The invention relates to a rapid threshold segmentation method based on gray level-gradient two-dimensional symmetrical Tsallis cross entropy, aims at the problems that approximate assumption exists in a conventional gray level-average gray level histogram and a whole solution space is required to be searched by calculation, so that segmentation is inaccurate and the efficiency is not high, and provides improved two-dimensional symmetrically Tsallis cross entropy threshold segmentation and a rapid recursive method thereof. The threshold segmentation method is higher in universality and accurate in segmentation; in order to realize accurate segmentation of a gray image, a new gray level-gradient two-dimensional histogram is adopted, and a two-dimensional symmetrical Tsallis cross entropy theory with a superior segmentation effect is combined with the histogram, so that the gray level image segmentation accuracy is effectively improved; the requirement for on-line timeliness of an industrial assembly line is met at the same time, a novel rapid recursive algorithm is adopted, and redundant calculation is reduced; and after a gray level image of the industrial assembly line is processed, the inside of an image zone is uniform, the contour boundary is accurate, the texture detail is clear, and at same time, good universality is provided.