In order to cultivate high-yield surfactant-producing strains and explore appropriate culture conditions. Nine water samples were collected from a combined station in ZJ2 area of Changqing oilfield, including four-stage treated water samples of biochemical pool, injected water from single well and produced water, and 23 strains were separated according to different characteristics. Seven strains producing surfactants were selected by using hemolysis characteristics of biosurfactants and blood plate culture medium[1]. Two strains with high activity were screened and their adaptability was evaluated in terms of NaCl concentration, oil content, pH value and temperature, and oil displacement simulation experiments were carried out. The results show that the strain has good temperature, salt and alkali resistance, and the biosurfactant has high interfacial activity, which can effectively reduce interfacial tension and improve oil recovery.