In order to improve the development effect of high-temperature low-permeability reservoir，the influence factors of surfactant flooding were researched. At the temperature of 114℃，the influence of interfacial tension（IFT），emulsification，wettability reversal and injection time on the injection pressure，displacement efficiency were proded by carrying out the surfactant flooding experiments in water-wet and oil-wet cores. The results showed that the lower the IFT between surfactant and crude oil，the clearer the increment of displacement efficiency and decrement of injection pressure. The faster the emulsion rate of surfactant，the higher the oil recovery; and the stronger the ability to reduce viscosity by emulsification，the better the pressure reduction effect. Meanwhile，it was beneficial to decrease properly the emulsion stability as for displacement. The wettability reversal of surfactant made the displacement become more effective even when the IFT was higher. Moreover，it made the effect of increasing oil production and decreasing injection pressure in oil-wet core better than that in water-wet core. Furthermore，the surfactant flooding at medium water cut stage could obtain maximal oil recovery via minimal input.