Abstract：On the base of direction of crack in various media，the porosity and fracture media are separated to partially random distribution fracture media，group distribution fracture media and fully random distribution fracture media. Then，the main seepage of rock mass with cracks is introduced in the percolation theory. On the base of fractal laws of crack number distribution，the simulation method is proposed，which can be used for the percolation of fully random distribution fracture media. By the numerical simulation method，the percolation phenomena and percolation law are studied，the mathematical expressions of percolation threshold that contains crack fractal dimension，initial fractal constants of crack and pore rate，are obtained.
