Mole rat, as a typical soil-burrowing animal, has a high working efficiency in digging hole in earth，its fore claws are main digging organ. The geometric characteristics of the claws of mole rats(Scaptochirus moschatus) was analyzed by stereoscopy, the quantitative analysis of geometrically characteristic features of the surfaces was performed by reverse engineering, and the second derivative and curvature of the surface profile curves were calculated. The curvature variation of longitudinal profile of claw changes gently and the longitudinal surface was smooth, which assures the tidiness of inner wall when mole rat dug holes. The curvature variation of transverse fitted curves shows a rapid change, and the bending of the transverse fitted curves increase from tip to rear, this kind of structure is easier for cutting in and hole-enlarging. The results provide some information for the design of the soil-cutting tools and excavation tools in energy-saving property and cutting efficiency.