Abstract: In the process of CO₂ geological sequestration, the mechanical properties of coal will be changed after supercritical CO₂ interacts with coal. Based on this, in this paper, Brazilian splitting test and variable angle shear test were carried out on anthracite under different test conditions, and the changes of tensile strength, shear peak strength, residual strength, internal friction angle and cohesion of coal under different test conditions were studied and compared from two aspects of dry/saturated moisture content and supercritical CO₂ soaking time（3, 5, 7 days）. The results show that the tensile strength, shear strength and residual strength of coal decrease with the increase of supercritical CO₂ soaking time, but the decreasing amplitude decreases gradually; the degradation effect of mechanical parameters of coal under the action of water + supercritical CO₂ is greater than that of drying test group; the internal friction angle and cohesion tend to decrease with the increase of supercritical CO₂ action time, but the effect of supercritical CO₂ on cohesion is more obvious, but the effect of internal friction angle is less.