Preparation method of xylooligosaccharide

The invention discloses a preparation method of xylooligosaccharide, and belongs to the technical field of xylooligosaccharide production.The method comprises the steps that xylan is obtained from agricultural fiber waste materials containing hemicellulose through alkaline extraction; a solid acid catalyst is added into an aqueous xylan solution, direct degradation is conducted, and a xylooligosaccharide solution is obtained; filtration is conducted to separate the solid acid catalyst from the xylooligosaccharide solution, and xylooligosaccharide is obtained.The method is low in cost, green in production, environmentally friendly and easy to operate, and the obtained product is high in quality.