Anthocyanin, a natural water-soluble pigment, has shown its unique research value in the field of intelligent packaging as it is environmentally friendly, safe and non- toxic, and sensitive to pH changes. With purple potato as the raw material, by keeping the total volume of the extractant unchanged and changing the volume ratio of glacial acetic acid and anhydrous ethanol in the extractant, the effect of the volume ratio of different glacial acetic acid and anhydrous ethanol in the extractant on the anthocyanin extraction effect was studied, and the color reactions of anthocyanin solution at different pH values were analyzed. The results showed that different proportion of extractant had a great influence on the extraction of anthocyanin from purple potato. Under the condition of certain volume of glacial acetic acid and anhydrous ethanol, the content of anthocyanin was the highest and the color effect was obvious by the analysis of ultraviolet-visible absorption spectrum and pH difference method when the volume ratio of glacial acetic acid and anhydrous ethanol was 1:1.