The invention discloses a method for producing xylose oligomer from bagasse. The necessary condition for the method for preparing xylose oligomer is enzymolysis reaction which can decompose xylan into xylose oligomer. The preparation method before enzymolysis reaction can have different results when different raw materials are adopted; and the results embody a concentrated reflection on extraction rate, quality and cost which determine the competitive power in the market, market share and benefit of the xylose oligomer. By using steam explosion and acidic microwave hydrolysis, the invention increases the extraction rate of xylan to 28%; anion-exchange columns are utilized to regulate the pH value of the material, so that the acid value of the coarse syrup can achieve the technical index range without adding acid or alkali, thereby achieving the goals of stabilizing the product quality and increasing the production/extraction yield. The invention is scientific and reasonable and has the advantage of high extraction rate; and the obtained xylose oligomer has the advantages of good quality and low production cost.