The invention relates to a sitodiplosis mosellana Gehin sex pheromone precursor compound as well as a synthesis method and an application of sitodiplosis mosellana Gehin sex pheromone. According to the synthesis method of the sitodiplosis mosellana Gehin sex pheromone precursor compound, CuCl and hydroxylamine hydrochloride are added to a Schlenk tube equipped with a magnetic stirrer under the protection of nitrogen gas, the tube is put in an ice bath to be cooled, 70% of a n-butylamine aqueous solution in percentage by mass is injected, chiral alkynol II is added, bromo-chiral alkynol III is slowly added, a reaction liquid reacts at the low temperature, a product is extracted with ethyl ether after the reaction ends, washed with a saturated sodium chloride aqueous solution and dried, a coarse product is obtained after pressure reduction, and chiral alkynol IV is obtained through purification with column chromatography. The prepared sitodiplosis mosellana Gehin sex pheromone has high optical activity; besides, the synthetic route is simple, the cost is low, and the sitodiplosis mosellana Gehin sex pheromone has commercial application value.