The invention discloses a digital image noise-proof categorizing technology based on geodesic distance. The technology includes: by an algorithm, properly selecting the initial centers of k categories; in the ith iteration, calculating the similarity of an optional pixel to k centers, and categorizing the pixel to category of the center with the shortest distance; calculating the mean value of each area, and updating clustering centers; if the values of all the k clustering centers are unchanged, stopping iteration, or else continuing iteration. By the technology, the influence of noise can be eliminated effectively to obtain clear cutting effect, the color space and the physical space of an image are combined to allow the pixels of each cluster to be close in color and space, and problems of overcutting and unobvious boundary are solved effectively.