In this paper, the superiorities of 3D finite element graphics system developed by OpenGL, such as high speed, powerful drawing function, convenient selection and feedback and nice visual effect are demonsrated through the comparison between GDI and OpenGL, which are both popular in graphics system at present. The paper also introduces drawing process of 3D model by OpenGL, display technology of concave polygon, back face culling and alpha blending, real-time rotation, translation, scaling, and efficient capture algorithm of PKPM-SAUSAGE software as well as the results display smoothing technology and color correction technology by shader programming in post-processing. Finally, the efficiency of OpenGL graphics display, rotation, translation, scaling and capture in PKPM-SAUSAGE software is verified by practical engineering examples.