Abstract: Study on permeation characteristics of engineering rock mass is a key technique to the analysis of seepage flow and stability design. Based on actual statistics used in the probability model for the typical structural plane of rock mass, a typical fracture network model is set up by discrete medium method, and a way to calculate the equivalent permeability coefficient tensor of the structural plane network of rock mass is put forward. An equivalent continuous medium model to reflect the anisotropy of seepage flow of rock mass is used to analyze the seepage flow problems of rock mass in areas of interest, which is set up specially for hydrogeological objects with sloping edges in mine-fields. As shown by examples, the technique is available to not only make a macroscopic seepage flow analysis in engineering rock mass, but indicate in depth the essence of seepage flow from fissures.