To reduce the damage of the inorganic alkali/ chemical surfactant dual oil displacement system to reservoir formation， improve the biodegradability of the oil displacement system，the interface performance between the biosurfactant rhamnolipid（RL）/ sophorolipid（SL）/monoethanolamine（MEA）or other organic alkali compound oil displacement system and the crude oil was analyzed，and through core displacement model，experimental evaluation of the enhanced oil recovery of RL/ SL/ MEA compound system to Shengli oilfield Zhan 3 block was carried out. The calculation results of Rubingh regular solution theoretical model showed that the RL and SL molecules in the biosurfactant mixed system could spontaneously attract on the surface adsorption layer and synergistically reduce the surface and interfacial tension of the solution. When the ratio of SL to the total surfactants was less than 0.3，the synergistic effect was stronger. The RL/SL/MEA compound system with 0.15% surfactant（SL accounts for 0.2 of both）and 3.5% MEA，could make oil-water interface tension reduce to 9×10^-3 mN/m，reaching the order of magnitude range of ultra-low interinterface tension. Core displacement model experiments showed that RL/SL/MEA oil displacement system could enhance oil recovery by 24.13% based on the water flooding. The RL/SL/MEA oil displacement system has a certain application potential in enhancing oil recovery of oilfield.