An experimental packed tower was set up to study the absorption of high-concentration CO2 in aqueous solutions of blended organic amine with diethanolamine (DEA) as base solvent, and N-methyldiethanolamine (MDEA), (N-2-hydroxyethyl) ethylenediamine (AEE), diethylenetriamine (DETA) and triethylenetetramine (TETA) as additives respectively. The effects of concentration and species of additives on the mass transfer performance, such as conversion rate of CO2 h, volumetric overall mass transfer coefficient KGae, and gas and liquid phase mass transfer resistance, were systematically examined. The results show that KGae and h increase with increasing of additive concentration when AEE, DETA and TETA are taken as additives. And the gas phase mass transfer coefficient kG and gas phase mass transfer resistance decrease, but liquid phase mass transfer resistance increases. For the additive of MDEA, the trends were just contrary to the above. In the absorption process of CO2 in two-component blended organic amine solutions, the values of KGae and h increase along the tower packing height, which follow the order of DEA-TETA > DEA-DETA > DEA-AEE > DEA-MDEA.