The invention provides a method for separating gasoline fraction and gasoline desulphurization. The method comprises the following steps: respectively using a gasoline fraction and an extraction solvent for penetration into an extraction segment from a lower middle part and an upper part, performing counter current contact, removing an extraction solvent for a lean solvent raffinate oil to obtainraffinate oil, performing back-extraction processing on the solvent-rich raffinate oil, returning the lean solvent soil to an extraction segment, introducing the solvent-rich soil into an alkene recovery tower from the bottom of a back-extraction segment, performing fractional distillation, returning an alkene-rich fraction part flowed out from the top of the alkene recovery tower to the back-extraction segment from the bottom, realizing circulation, leading a part of the material as an alkene fraction, and performing solvent separating extraction on a sulfur-rich fraction flowed from the bottom of the alkene recovery tower to obtain the extraction oil. The provided separating method can realize effective separating for the alkene in a gasoline fraction, is benefit for reducing the alkenecontent in a gasoline product, can guarantee no influence for octane number, realizes deep desulphurization, realizes structural adjusting of a gasoline product, and can obtain the high-quality gasoline.