Abstract: 3D scene which major element is up-and-down terrain is the foundation of all the 3D emulator and to offer an active ground or background space.It is widely used in simulation，virtual reality and games.Currently most optimized work emphasize particularly on different terrain theories and arithmetic and less attention on how to optimize the base arithmetic in great 3D scene building field.This article put forward a new method which using the vertical-array arithmetic to build fleetly the 3D scene.Compared to the list arithmetic，farther predigest the process then improve the efficiency.