Abstract: The extraction and stability of the pigment of the purple sweet potato were studied.Microwave extraction method, select the proportion of solvent, time, temperature, solid-liquid ratio as the extraction of factors, single-factor experiments and L 9 (3 4) orthogonal experiment to explore the extraction process of the pigment in the purple sweet potato.The effect of pH, temperature, different metal ions, oxidizing agents reducing agent, the impact of different food additives and other factors on the stability of the pigment of the purple sweet potato, and purple sweet potato pigment oxidation resistance were studied.The result showed that:purple sweet potato pigments with maximum absorption peak at 450nm, the mass fraction of 10% citric acid solution, the temperature of 30℃, the power of 75W, time of 15min, solid to liquid ratio of 1:15, purple sweet potato pigment the extraction rate was higher, the pigment of the purple sweet potato better stability, and had a strong antioxidant activity.