Under the affect of water, slate features are charged, such as: physics, chemistry and mechanics, etc. It is a very complex process to water and rock interaction. And the quantify index that describes the process is still difficult to obtain.Aimed at the characteristic of water immersed collapse of slate, this article used the correlation fractal dimension of fractal theory to study the characteristic of collapse of slate and found the fractal model of collapse of slate. The fractal dimension of slate collapse is solved through quality. A series of fractal dimension values were obtained through collapse experiment. According to these values changing, the regularity that fractal dimension of slate collapse is changed with the water-immersed time increasing is obtained. This model was applied to solve the problem of water-immersed softening and collapsing of slate when constructing deep-long tunnel in west line of S-N water transfer project.
