Clutter caused by reel and ocean animals is the primarily interference for active sonar. How to classify and identify underwater vehicle echo between reel and ocean animal echo is the most confusing problem that affects the performance of active sonar. Characterization and application mode of underwater target omnibearing echo characteristic are studied for the application of active sonar target identification. A method of estimating the acoustic scattering function based on highlight model is presented, through which underwater target acoustic echo characteristics could be well characterized by statistical feature, and the method is more suitable for the application in active sonar classification. Based on the method studied in this paper, statistical feature of echo highlight is extracted from lake acoustic scattering test of scalled benchmark submarine model.