Abstract: A digital image-based (DIB) numerical method is used in two-dimensional coupled multiphysics analysis of fractured rock masses by actually taking into account the heterogeneous spatial distribution of rock structures—main fractures, minor fractures and intact rock. The digital image processing technique is developed to identify and classify these structures in the fractured rock masses and to translate spatial distribution of rock structures to spatial distributions of material parameters (permeability, Young’s modulus, heat conductivity, etc.). Then the characterized material parameters of rock masses are directly imported into our newly developed multiphysics simulator, a MATLAB and FEMLAB based Simulator of Coupled Multiphysics in Rock, to evaluate the effect of heterogeneity on the coupled multiphysics process in fractured rock masses. The DIB numerical results of coupled multiphysics process show that DIB technique is capable of characterizing the heterogeneity and fracture structures of fractured rock masses and that the DIB numerical method may be a new approach to predict more realistic numerical results.