Abstract: After having lucubrated the existent algorithms of 3D-buffer boundary generation,aiming at a kind of special morphologic geographic component,namely,singular value surface,and by establishing the union principle for singular value surface,the paper has brought forward the algorithm of 3D-buffer boundary generation based on rolling ball model.Besides,the paper expatiates the keystone and solution steps of the algorithm,meanwhile,the complexity of the algorithm is also analyzed.At last,under the condition of VC++,some experiments generating the 3D-buffer boundary of Grid-DDM,have been done to validate the algorithm.The experiments show that the algorithm is characterized by high execute efficiency,reliable precision,cushy adaptation of complicated singular value surface configuration and so on.