Abstract: Based on digital core technology, this study finely characterizes the real morphology and spatial distribution characteristics of fractures and vugs, and constructs a 3D geometric model of fractured-vuggy media that couples matrix with fractures and vugs. Aiming at the differences in flow characteristics between fractured-vuggy regions and matrix, a Darcy-Brinkman mathematical model coupling free flow and seepage flow is established to conduct mixed-scale flow simulation research. On this basis, a calculation method for the 3D equivalent permeability tensor is proposed, and a sensitivity analysis of the influencing factors of equivalent permeability is carried out. The research results show that: fractures and vugs lead to the heterogeneous distribution of reservoir pressure and flow velocity, and fractures have a more significant impact on the overall pressure distribution; fractures significantly improve the seepage capacity in their extension direction, and the equivalent permeability tensor of fracture-vug reservoirs exhibits stronger anisotropy; the equivalent permeability of the media is more significantly affected by fracture length and the angle between fractures and the pressure drop direction. This research holds important guiding significance for improving the calculation accuracy of physical properties of such reservoirs and realizing the scale-up of reservoir parameters.