Application of sophorolipid

The invention discloses application of sophorolipid. Serving as a microbial source bi-directional humectant having a physical moisture retention damp-proof function and an aroma enhancement function, the humectant is natural, non-toxic and harmless. Sophorolipid comprises any one of lactone type sophorolipid and acid type sophorolipid or mixture of lactone type sophorolipid and acid type sophorolipid. The humectant can be applied to cigarettes, tobacco shreds, tobacco sheets and other tobacco products. The humectant is evenly sprayed on the tobacco shreds, the spraying proportion is 0.05%-2.0% of the weight of the tobacco shreds, and the humectant has effects of obviously retaining tobacco shred moisture under low humidity conditions and obviously controlling moisture increase under high humidity conditions; the moisture retention and dampproof effect is more excellent than that of propylene glycol and glycerin, and the humectant is an excellent natural bi-directional humectant.