The invention discloses a method for separating active components from a petroleum sulfonate. A chromatographic technique is adopted, a petroleum sulfonate sample is subjected to segmental cutting ina gradient elution mode according to time periods and divided into 24 components, and the components with similar structural compositions are combined to obtain 14 components with different structuresaccording to results of mass spectrometry analysis. These obtained components are subjected to interfacial activity and emulsifying property tests separately, and the components with better interfacial activity and emulsifying properties in the petroleum sulfonate sample are screened and accurately separated to provide accurate raw material selection guidance for production and preparation of petroleum sulfonate samples with excellent performance.