The traditional segmentation of typhoon cloud based on mathematical morphology usually uses round or diamond-shaped template to segment satellite images. This conventional approach fails to keep a good typhoon original form information after large or multiple erosion or dilation. In order to solve this problem, the authors studied the theory and method of typhoon segmentation with priori features in this paper. Concretely speaking, the authors first extract the general form of typhoon cloud as a morphological template, and then extract typhoon cloud by morphology methods. With TBB data of FY2C, NO.200809 typhoon obtained at 6:00 p.m on July 28 as an example, the authors made a template according to the shape of the typhoons to erode clouds images, and then made a detailed comparison as well as analysis of different template shapes or sizes of the cloud segmentation results. The results show that the priori features templates segmentation results can not only well retain the characteristics of typhoon cloud but also preserve most information after cloud erosion.