In view of the complexity, time-consuming and low accuracy of the existing tongue image segmentation methods, this paper proposes a new tongue image segmentation method based on an improved geometric active contour model. The algorithm uses the result of watershed transformation controlled by markers as the initial curve of the active contour model, and then uses the principle of LBF model to construct a new evolutionary stop function of geometric active contour model. Experimental results show that this method can not only reduce the influence of noise points in the image on contour deformation, but also improves the speed of convergence, and achieve satisfactory tongue image segmentation results.