Preparation method of xylooligosaccharide

The invention provides a preparation method of xylooligosaccharide, and belongs to the technical field of functional oligosaccharides, the preparation method comprises the following steps: mixing peanut shell powder with water to obtain a peanut shell powder wet material; carrying out extrusion puffing treatment on the wet peanut shell powder to obtain a puffed material; mixing the puffed material with water, and extracting to obtain an extracting solution; mixing the leach liquor with xylanase, and saccharifying to obtain saccharified liquor; sequentially carrying out decoloration, ion exchange, chromatographic purification, concentration and drying on the saccharified liquid to obtain the xylooligosaccharide. Peanut shells are used as raw materials, so that the problem of recycling a large amount of peanut shell wastes every year in China is solved; the extrusion puffing principle is applied to the large-scale production of the xylooligosaccharide; water is used as an extraction solvent of xylooligosacchari