Abstract: In order to obtain the geometry and topology of a 3D model,a skeleton extraction method based on the convex hull and the oriented bounding box（OBB） is presented in this paper.It firstly divides the mesh into several parts;computes the convex hull of each part’s point set as its approximation,and uses the convex hull’s centroid as the original skeleton point.Then it looks for the overlapping point set between two adjacent parts by using OBB,determines the centroid of the overlapping point set as the joint point.It finally connects original skeleton points with joint points and removes redundant points to get the entire skeleton.Experimental results show that this skeleton extraction method is simple,fast and effective.It guarantees the connectivity and centrality of the skeleton,which can provide useful information for skinning joint animation,3D model shape analysis,etc.