A design method of an application software is proposed, which can not only process complex data and graphic，but also has distinctly structure，convenient User Interface(UI) and the function of multi-view contrast display. By using Multiple Document Interface(MDI) structure to isolate data-display and logic processing，then applying the double-buffing to the self-adaptive drawing, complex data-processing and graphic displaying are realized in VC++ program with mixed programming based on dynamic link library. By means of realizing the test soft which can draw 2D and 3D graphics, the effectiveness of the proposed method is verified.