The computer may cause the serious delay when it processes the large 3D mesh, which influences the visual effect of the scene. Taking the visual effect as the primary condition, the simplification method of 3D mesh model and QEM method are studied. Firstly the simplification methods are classified. Then the error evaluation methods of the simplification mesh are studied. Finally the QEM method is implemented based on OpenGL. It only takes 111.78 ms to accomplish 93.7% of the simplification, meanwhile the visual effect is also remained.