The invention discloses an arylbenzofuran compound with antioxidant activity and a preparation method and application thereof. The arylbenzofuran compound with the antioxidant activity is separated from tobacco root and stem, has a molecular formula of C17H16O3 and a structural formula of A and is named as 2-(4-metoxybenzene)-3, 5-dimethylbenzofuran-6-ol. The arylbenzofuran compound with the antioxidant activity is obtained by taking the tobacco root and stem as raw materials through condensate extraction, silica-gel column chromatography and high-performance liquid chromatography. Experimental results show that the arylbenzofuran compound with antioxidant activity is good in antioxidant activity and capable of significantly prolonging the service life of flavor agent. When serving as a flavor agent antioxidant agent, the arylbenzofuran compound with the antioxidant activity can effectively inhibit oxidative deterioration, prolong the service life and avoid affecting smoking quality of cigarettes.