The emulsifying ability of surfactant has a great impact on improving the oil displacement effect after water flooding development of low-permeability reservoir. In order to enhance the emulsifying performance of surfactant oil displacement system and improve oil displacement efficiency，anion non Gemini surfactant GEY-2 with good interfacial activity and non-ionic surfactant 6501 with strong emulsifying ability were combined，a strong emulsion composite surfactant flooding system suitable for low permeability reservoir was developed，and its comprehensive performance was evaluated. The results showed that the strong emulsifying composite surfactant oil displacement system had good temperature resistance and salt resistance. Under the conditions of high temperature and high salinity，the oil displacement system composed of 2000 mg/L GEY-2 and 3000 mg/L 6501 could still maintain urtralow oil-water interfacial tension，being of 10^-3 mN/m. The emulsified water rate of the elusions，which was formed through combing the composite surfactant oil displacement system with the crude oil in volume ratio of 7∶3，was 90.2% and 61.2% after placed at the temperature of75 ℃ for 10 min and 100 min，respectively，which indicating the system had strong emulsifying property. The system had good anti-adsorption performance，which could reduce the waste of oil displacement agent and effectively ensure the oil displacement effect. The composite surfactant flooding system had a good oil displacement effect on low-permeability cores. When the core permeability was 11.38×10^-3 μm²，the oil recovery could be enhenced by more than 20% by injecting 0.5 PV strong emulsion composite surfactant flooding system after water flooding. The field application results showed that after the implementation of strong emulsion composite surfactant displacement measures in the low permeability block of H oilfield，the injection well pressure increased，the daily oil production of corresponding oil wells increased from 2.20 t to 5.41 t，and the average water cut decreased from 89.2% to 71.5%，which achieved a good oil increase effect.