The large-scale deployment of post-combustion carbon capture exerted additional pressure on water resources. In this work, the feasibility of forward osmosis driven by unloaded or CO2 loaded Monoethanolamine (MEA), N-Methyldiethanolamine (MDEA) and their blended absorbents for water replenishment was investigated. The results indicated that the water flux of unloaded MDEA solution increased from 12.92 LMH to 18.72 LMH at amine concentrations from 1 M to 5 M, which was much higher than that of unloaded MEA solution, owing to the huge differences of the osmotic pressure. As the MEA and the MDEA were blended, some synergistic effects may work to result in the higher osmotic pressures and the lower water fluxes of MEA-MDEA blended solutions than the summation of the individual ones, respectively. Furthermore, as the CO2 was absorbed by the MEA-MDEA blended solution, the water fluxes of the CO2 loaded solutions increased nonlinearly. Specifically, when the CO2 loading was lower than a specific critical value, the growth of the water fluxes of MEA-MDEA blended solutions with the CO2 loading gradually slowed down, caused by the increase of the solute diffusion resistivity. However, when the CO2 loading exceeded the critical value, the water fluxes of blended solutions become increasing faster with the CO2 loading, probably due to the increase of the concentration of HCO3– and MEAH+. On the other hand, there was an optimal CO2 loading value that minimized the reverse solute flux.