The invention aims to provide a method for preparing lavender absolute oil through biological fermentation and application thereof. The method comprises the steps that a certain proportion of water isadded into a dried lavender spike, microwave pretreatment is carried out, then acid is added for hydrolysis, a compound biological agent is added for incubation and fermentation, then backflow extraction is carried out on ethyl alcohol, a filter screen is used for filtration, a lavender fermentation extracting solution is obtained, after decompression concentration, precipitation and quiescenceare carried out for a night on absolute ethyl alcohol, the precipitate is removed through centrifugation, and the lavender absolute oil is prepared through the biological fermentation. The invention further provides the application of the lavender absolute oil prepared through the biological fermentation in perfuming a cigarette, the lavender absolute oil is in good coordination with the smoke, the cigarette fragrance is clear and rich, the fragrance is natural and abundant, not only does the cigarette have the special fragrance of fresh lavender and wood fragrance, but also the cigarette hascompound bake, chocolate, fruit, sweet aroma and the like; compared with a reference material, the irritation is reduced, the impurities are reduced, no bitter exists; and the defects of too single and strong fragrance, strong irritation and bitter remaining taste of lavender absolute oil without the biological fermentation are overcome.