<p>With the intensification of global warming, geological carbon dioxide sequestration has gained increasing attention as a pivotal carbon neutrality strategy. Notably, when carbon dioxide is injected into porous media, it typically exhibits distinct fingering patterns that significantly influence storage efficiency and stability. Using a resolved CFD-DEM-VOF coupling framework, this work systematically investigates and reveals regime-dependent particle migration mechanisms during supercritical carbon dioxide (SC-CO₂) injection into saline water, demonstrating fundamentally different behaviors under viscous, capillary, and stable fingering conditions. In addition, a rigorous comparative study with a single-phase flow model is carried out. The results demonstrate that in capillary and viscous fingering patterns, narrow fluid channels form within the fluid field, with pore clogging predominantly concentrated along the channel flanks. The affected particles are primarily those adjacent to the fluid channels. In contrast, under stable fingering conditions, shifting high-velocity zones lead to more randomized pore clogging distributions, resulting in broader particle mobilization and greater particle loss. Compared to single-phase flow models, the emergence of high-velocity regions and enhanced fluid field instability during displacement significantly strengthen particle migration capacity.</p>