Method for preparing enriched xylobiose to xylotetraose from eucalyptus hydrothermal pretreatment liquid

The disclosure discloses a method for preparing enriched xylobiose to xylotetraose from a eucalyptus hydrothermal pretreatment liquid. The eucalyptus hydrothermal pretreatment liquid 5 is sequentially treated with calcium hydroxide, activated carbon adsorption and endoxylanase to obtain a xylo-oligosaccharide-enriched sugar liquid. Then, the sugar liquid is treated with membrane dialysis and freeze-dried to obtain a xylo-oligosaccharide powder rich in xylobiose to xylotetraose. By means of the method of the disclosure, the operating cost of equipment in the process of refining xylo-oligosaccharide can be effectively reduced, the environmental 0 pollution load can be alleviated, the yield and purity of the xylo-oligosaccharide can be increased, the high-value utilization of the hydrothermal pretreatment liquid is realized, and the market price of the xylo-oligosaccharide is reduced to a certain extent.