Abstract: The optimum dichotomy based on the theory of or- dered specimen cluster analysis provides an objective and reliable criterion for layering,but because of its excessive calculating in application,the popularization is badly af- fected.By recognizing the single layer section of logging data,an optimum dichotomy based on mean value of sin- gle layer is introduced in this paper.On the basis of single layer division,a successive optimum dichotomy of logging series is realized,which greatly reduces the calculating a- mount.Through VB language programming,the method is popularized and works with a quick speed and favorable effect.