The invention discloses a method for quantitatively analyzing lactones aromatic substances in mainstream smoke of fine cigarettes. The method is used for determining the content of three types of main lactones aromatic substances including alpha-angelica lactone, gamma-caprolactone and dihydroactinidiolide in the mainstream smoke of the fine cigarettes based on a gas chromatography-tandem mass spectrometer, and comprises the steps of preparing an internal standard solution, a standard working solution and a sample solution, analyzing by the gas chromatography-tandem mass spectrometer, and calculating a determined result and the like. The optimized detection method disclosed by the invention is relatively simple and convenient, and sensitive to respond and can be used for accurately quantitatively analyzing; matrix interferences are effectively avoided, and the linear correlation is relatively good; the detection limits of the three types of main lactones aromatic substances including the alpha-angelica lactone, the gamma-caprolactone and the dihydroactinidiolide are 4.23ng / piece, 1.86ng / piece and 1.87ng / piece respectively, the repetitive rates are 1.31%, 3.57% and 1.93% respectively, and the standard recovery rates are 108.3%, 115.4% and 89.4% respectively. The method disclosed by the invention has high sensitivity and relatively good repeatability and recovery rate, and is applicable to quantitative analysis of trace target matters in complicated matrixes of the smoke of the fine cigarettes.