Objective: To propose a simple image segmentation method,which is based on the teeth image acquired by oral cavity endoscope. Methods:Firstly,removing the sequins of the image by the open operation of morphology;Secondly,removing the noise of image by the value of filtering;Lastly,segmenting the image through the parameters gained by the gray value of the image,detecting the edge of the teeth image and corners. Results:This method can separate the teeth out from the image effectively,and the corners can offer some available parameter for the 3D reconstruction of the teeth. Conclusion:The method can segment the teeth from the image effectively.