The invention belongs to the technical field of production of filter sticks of fine cigarettes, and particularly relates to a butter-flavor cellulose acetate tow and application thereof in fine cigarettes. The cross section of the cellulose acetate tow is in a Y shape; according to the specification requirements of the tow, the single denier is 6.0 den-11.0 den, and the total denier is 15000 den-17000 den. In the preparation of the butter-flavor cellulose acetate tow, before a tow enters a crimping machine after being ejected out of a spinneret, the tow is oiled through an oiling agent system with butter-flavor essence added, wherein the mass ratio of the butter-flavor essence added in the oiling agent system is not smaller than 0 but not larger than 5%. The smoking effect of fine cigarettes can be specifically and significantly improved by changing the aroma enhancing way, the improving effect is obvious, and thus the tow has high application value and great application and popularization significance for the design, development, production and selling of new fine cigarettes.