Abstract: In the deep high-stress and low-permeability coal seam extraction, the compaction and expansion of coal, the deterioration of mechanical properties, the transformation effect of the fracture network, and the permeability evolution are closely related to the effective stress of coal under true triaxial mining environment (σ_eij=σ_ij−α_ijp, where σ_eij is the effective stress, σ_ij is the principal stress, α_ij is the effective stress coefficient, and p is the pore pressure), and the key to quantify the effect of the effective stress is to determine the anisotropic properties of α_ij. Anisotropic effective stress coefficient and permeability evolution characteristics of coal during CO₂ fracturing under different shallow and deep stress states are analyzed in this study. The results indicated that the α_ij of coal revealed anisotropy during the CO₂ fracturing induced damage process, showed a uniform increase with the increase in damage degree, the anisotropy of α_ij subsequently increased as well, and always exhibited α₁ > α₃ > α₂. The elevation of true triaxial initial stresses constrained the propagation of gas fracture-inducing cracks. α_ij in a state of high stress was lower than that in a state of low stress under initial fracturing conditions. For different fracturing directions, during the initial damage stage, it is observed that α_ij shows α_F > α_B > α_D (α_F is the effective stress coefficient in face cleat direction, α_B is the effective stress coefficient in butt cleat direction, and α_D is the effective stress coefficient in bedding direction.). As the fracturing progresses, α_D demonstrated a more significant increase compared to α_B and α_F, indicating that natural fractures distributed along bedding planes are more prone to propagation under the driving force of high-pressure gas. The tensile stress generated by CO₂ fracturing of coal could stimulate the tip fissures to combine with beddings and cleats to generate tilted fissures, and form a composite network of shear or tensile-shear fractures, which greatly increased the seepage channels and enhanced the permeability and the effect of gas extraction. However, the gas extraction effect would be worse under high stress conditions, and the permeability enhancement when fracturing along the cleat direction was better than that when fracturing in the perpendicular bedding direction. Based on the Kirsch stress superposition principle and the tensile stress criterion, a prediction model for the breakdown pressure of the coal when CO₂ fracturing was established. The effect of quantifying α_ij on the breakdown pressure and fracture extension criterion of coal was analyzed. Under the condition of medium differential pressure, neglecting α_ij would also exaggerate the role of pore pressure to offset the principal stress, resulting in the calculated deformation being smaller than the actual deformation. Quantifying α_ij avoided the underestimation of coal seam stability, and the CO₂ fracturing pressure could be increased to enhance gas extraction and effectively improved the level of gas control in the mine.