Abstract: To improve the efficiency of rendering multi-resolution Geometry IMage(GIM),we introduce the concept of enum-quadtree into conventional quadtree,and use each node of enumquadtree as the independent rendering unit,which can reduce the number of drawing function greatly.Aiming at the phenomenon that the edges of GIM's different level occur cracks easily when real-time rendering,by means of using the enum-quadtree structure,we use step function to repair cracks of the inner node in data preprocessing stage,and use the arctangent function to control points shift to repair cracks among different resolution nodes on GPU in real-time rendering stage.Experimental results show that enum-quadtree structure can make full use of the power of GPU's parallel processing,and effectively improve the rendering efficiency.Furthermore,crack process algorithm is easy to implement on GPU and can obtain high frame rate with better drawing effect.