Abstract：Fracture saturation is a common phenomenon in geosciences. Based on the FEM code，the mechanisms of fracture saturation and the factors influencing the spacing of the fracture are analyzed. The results show that the stress state between the adjacent fractures changes from tension to compression as the ratio of fracture spacing to layer thickness decreases. This stress state transition precludes further infilling of fractures，which results in the fracture saturation. The process of the fracture saturation is vividly represented. And from results of the numerical simulation，the rules of initiation and propagation of the fractures is recognized.
