Method of preparing xylitol from crop straws

The invention discloses a method of preparing xylitol from crop straws. The method comprises the following steps of: performing steam explosion treatment on the crop straws; performing water cooking treatment; treating a water cooking liquid by a microwave-assisted acid hydrolyzation method; performing neutralizing and purifying treatment; and performing sodium borohydride alkaline solution treatment to obtain xylose. A process of converting hemicelluloses cooked and recovered from the straws through steam explosion pre-treatment as a raw material into xylitol is taken as an important technical composition of fully utilizing straw biomass components, sulfuric acid is added into the water cooking liquid obtained by cooking the steam explosion straws to be hydrolyzed to obtain xylose, and sodium borohydride is added through neutralization and resin purification to be reduced to obtain xylitol, wherein the conversation efficiency of xylose reduced to xylitol reaches 94% above, and the process is simple and effec