With the oil-water interfacial tension as the property evaluation index, the binary combination flooding composed of organic alkali ethanolamine（MEA）and petroleum sulfonatewas optimized as follows, 0.30% SLPS+0.30% MEA. On this basis, the interfacial ability, salt resistance, temperature resistance, emulsification and oil displacing properties of the optimized binary combination flooding MEA/SLPS system was evaluated by comparing that of common used binary combination flooding system——inorganic alkali/surfactants（NaOH/SLPS）system.The experimental results showed that there was no large difference with respect to the ability of reducing oil-water interfacial tension between the MEA/SLPS system and that of NaOH/SLPS system, both could make the interfacial tension be below of 10^-3 mN/m, however, with MEA/SLPS system, the oil-water interfacial tension could be reduced to the lowest value within shorter time than that with the NaOH/SLPS system. The MEA/SLPS system was better in the aspects of salt resistance, emulsification and oil-displacing ability, the salt resistance being up to 30000 mg/L，the enhanced oil recovery being up to 13.2%, except for its worse ability of temperature resistance, being only 70℃.Within certain temperature range, organic alkali could substitute inorganic alkali used as some kind of chemical flooding alkali in the future with better effect of oil displacement.