Abstract: Drilling Simulator Graphic System is a subsystem of Drilling Simulator. The System is mainly as form of threedimension animation on computer to present vivid objects of drilling site and the operation to users under the condition away from the real situation. Because the system is very complicated, round trip procedure is taken as example to describe how to design the system with Object Oriented. At the beginning, the technological process of round trip is introduced, and then the way to extract the action and object of animation from the technological process is emphasized. After the analysis, how to design the class and program for the technological process in detail is furtherly demonstrated. The practice has proved thatusing the object oriented design, the system has many characters such as strong expansibility and good flexibility.

Key words: drilling simulator, drilling simulator graphic system, object oriented, virtual function, lateness binding