The affinity effect likely attributes to the sum of adsorbate molecular multipole moments and polarizability. Isotherms of SO2 and NO exhibit higher degree of curvature and morphogenesis of their isotherms are probably decided by adsorbate–adsorbent interaction transition. Molecule CO2 exhibits the most efficient molecule packing on both zeolites, while SO2 takes the highest freedom in cavities. Better performance is found on 5A than 13X zeolite at adsorbing SO2, NO and CO2 through multi-component adsorption equilibrium simulation.