Abstract: The real-time and realistic skin deformation of 3D virtual human is one of the most important research fields in computer animation.A skin deformation method based on cross-sectional contour is widely used because of its quick speed and good continuity.But it is difficult to express the slight skin deformation at the joints whose freedom degree changes largely.Thus，a method of increasing the sections at such joints to express the slight skin deformation is introduced and it gets anticipative effect.This method can solve the distortion problem of skin deformation at joints，and not reduce the real time.Ideal skin deformation can be obtained by using this method.