The utility model discloses a ternary acetate fiber composite cavity filter stick capable of reducing volatile phenolic compounds in cigarette smoke. The ternary acetate fiber composite cavity filterstick comprises a filter element, an inner wrapping layer and an outer wrapping layer, wherein the inner wrapping layer and the outer wrapping layer wrap the filter element; wherein the filter elementis a ternary composite filter element and is formed by sequentially combining a common cellulose acetate fiber section, a chitosan oligosaccharide grafted polyacrylic acid adsorption material particle section and a common cellulose acetate fiber section. According to the utility model, three-section compounding is adopted; the chitosan oligosaccharide grafted polyacrylic acid adsorbing material is used as a harm reducing component; the grafted acrylic acid part in the chitosan oligosaccharide grafted polyacrylic acid adsorption material particle segment contains a large amount of carboxyl; and phenol, ammonia and the like are adsorbed through hydrogen-bond interaction, so that the content of harmful substances such as phenol, ammonia and the like in mainstream smoke can be further effectively reduced while the adsorption capacity of the original filter stick is maintained, and the aims of reducing the harm of cigarettes and improving the smoking quality of the cigarettes can be betterachieved.