The invention relates to an oil-displacement surfactant composition, a preparation method and application, and mainly solves the problems that conventional surfactants are bad in oil displacement efficiency in the process of tertiary oil recovery, and an oil displacement system damages stratums and oil wells, corrodes equipment and pipelines and cause demulsification difficulty because of a contained inorganic base. The employed oil-displacement surfactant composition comprises a cationic surfactant and an anionic-nonionic surfactant with the molar ratio of 1:0.01-1:100, wherein the anionic surfactant is at least one selected from quaternary ammonium salts or quaternary amine bases, and the anionic-nonionic surfactant has the molecular general formula shown in the specification, and the in general formula, M is any one of alkali metals, alkali earth metals and ammonium radical. The technical scheme relatively well solves the above problems, and is applicable to an enhanced oil recovery process of oil fields.