A new algorithm for image segmentation named radar algorithm is proposed in this paper. The proposed algorithm is based on SOM network model, the mathematical morphology and physical simulation. This new algorithm is simple and easy to use while with powerful functions. The time complexity of the radar algorithm is 90*O(n3). Further, the proposed algorithm has better robustness. The experimental results show that the Radar algorithm is an effective and powerful image segmentation method. It has wide applications in image segmentation especially in the processing of images with discontinuous edges.