Abstract: Seepage through fractures in a geologic body is a very complex issue. Usually, its macro-seepage characteristics can be described by the equivalent permeability tensor. Based on the superposition algorithm for calculating the equivalent permeability tensor for multiple sets of infinity parallel fractures, this paper proposes a kind of more general superposition algorithm by introducing the concept of the through coefficient of fracture. Combining with the computer-generated technology of the random fracture network, the method can be used to approximately estimate the equivalent permeability tensor of two-dimensional random fractures.