Abstract: Ultra-low interfacial tensions can be formed between crude oil and the binary compound flooding system, which is non-alkali surfactant added with polymer. Compared with ASP flooding, without alkali in the formula, the visco-elasticity of the polymer can be fully developed, and the phenomena of corrosion and scaling can be reduced. Through the research on physiochemical performance of non-alkali surfactant, the evaluation on compatibility, stability, shearing resistance, emulsibility, rheological behavior and visco-elasticity of oil-water conditions in pilot area has been carried out. Meanwhile, the oil displacement mechanism research on enhancing oil displacement has been conducted from the microscopic aspect, providing guidance for big-scale pilot testing of binary compound flooding system and the laboratory testing results show the recovery is enhanced by 13%.