Abstract: Scenes are commonly rendered by the polygon approach. In the method proposed in the paper on backface culling, at first the normal of the polygons inside the scene is normalized to unit vectors, then the start point of the normal is moved to the origin and thus these unit vectors are surely distributed on the unit sphere. The surface of the unit sphere is divided into several parts and each part topologically mapped into a reference plane. With the reference plane, we can get the space that the normal of the polygons locate and then calculate the topological mapping point on the disk boundary of the polygon normal. For a given scene, such pre-calculation only need once. When the position of the view vector is being changed, for each space, the topological mapping point of the view vector and the center back boundary are calculated dynamically. To each polygon, on the projection line, backface test could be made according to the position of its normal mapping point and the mapping point of the viewing direction. Experiments show that the algorithm is rapid, robust and easy for implementation.