Molecular dynamic simulation is employed to investigate the fluid distribution of pure hydrocarbons, i.e., C-1, C-2, nC(3), nC(4), and nC(5), in a hydrocarbon-wetting nanopore. SO2 and CO2 are then introduced into this nanopore to explore how SO2 and CO2 affect the hydrocarbon adsorption in an organic pore. Adsorption selectivity and replacement efficiency of SO2 over hydrocarbons are subsequently calculated and compared with those of CO2. The performance of SO2 and CO2 in enhancing hydrocarbon recovery from nanopores is thus evaluated. After introducing SO2 or CO2 into the "hydrocarbon-saturated" pore, the density of hydrocarbons in the adsorption layer decreases, while the density in the pore center increases. It suggests that both SO2 and CO2 can replace the adsorbed hydrocarbons from the pore surface. In addition, higher adsorption capacity is observed for CO2 than that for C-1 but smaller than those of the heavier hydrocarbons, i.e., C-2, nC(3), nC(4), and nC(5). Comparatively, SO2 exhibits a stronger adsorption capacity than C-1, C-2, nC(3), and nC(4), suggesting its potential for enhancing the recovery of heavier hydrocarbons from organic pores. We expect this strategy will inspire new perspectives for flue-gas treatment and recovery of shale resources using flue-gas injection.