Abstract: Research on the evolution of coal permeability is of great theoretical and engineering significance for the efficient development of coalbed methane and the prevention and control of coal mine gas disasters. Traditional permeability models are mostly established on the basis of cubic or capillary models, in which fractures are idealized as smooth parallel plates or circular tubes of uniform diameter to construct permeability evolution models for smooth fractures. However, these models overlook the effects of fracture roughness and pore shape differences, leading to deviations in prediction results. To address this, the present study combines fractal geometry theory with fundamental principles of seepage mechanics. Based on the assumption of conical roughness elements and the fractal distribution of their sizes, a quantitative characterization method for fracture roughness is established, from which the effective average height and relative roughness of the roughness elements are derived. Consequently, the effective aperture of fractures is reasonably modified to account for the influence of roughness. On this basis, for two typical pore shapes, namely capillary and cubic forms, the modified effective aperture is incorporated to construct permeability evolution equations separately, and a multi-factor coupled permeability model incorporating roughness, stress, and adsorption is established. The validity of the model is verified using seepage experimental data, and a parameter sensitivity analysis is conducted to quantitatively investigate the regulatory effects of roughness parameters and pore shape ratio on permeability evolution. The results indicate that the proposed model can accurately fit the evolutionary trend of permeability with decreasing gas pressure. Increased roughness significantly suppresses permeability, and the cubic model exhibits higher sensitivity to parameter variations compared with the capillary model. In addition, pore shape also exerts a notable regulatory influence on permeability. The model developed in this work deepens the understanding of complex seepage mechanisms in rough fractures and can provide a reliable theoretical basis for engineering practices such as coalbed methane productivity prediction, drainage scheme optimization, and gas disaster prevention.