Abstract: The aim was to establish a method of extracting and purifying Water-Soluble xylan from sweet corn cobs. Xylan was extracted from sweet corn cobs through stewing method and the optimized conditions of the extraction method were confirmed by the orthogonal experiment. The extraction efficiency was determined subsequently. Simultaneously xylan from sweet corn cobs was purified by Capto Q after disposing of decoloration and removing protein. The results were shown as follows:sweet corn cobs were soaked by 3g/L H2SO4 after 12h, the ratio of solid to liquid 1∶ 10 (g∶ mL) , the temperature and time of stewing were 150℃ and 60min, respectively. Using column chromatography, the dry powder content and yield of xylan were 82. 7% and 51. 8%, respectively. The optimum extraction ratio of this method was 27. 32%. In this study, the water-soluble xylan of sweet corn cobs was extracted and purified, the supporting of experiment data were provided for the future xylan industrialization.