The experimental process of extracting furfural from walnut nutshell powder by using the two -step method was studied in this paper. Firstly, the xylose extract was obtained by acid hydrolysis. Then, the influence of the single factor including the liquid ratio to material, hydrolysis reaction time and hydrolysis reaction temper- ature on the extraction rate of xylose was explored. Then, the above hydrolysis reaction was optimized by the combination experiment of the Box-Behnken center and response surface methodology based on the single factor. The optimum reaction conditions are found as follows: the ratio of the reaction liquid to the material is 24.48 mL/ g, the reaction time being 3.17 h, and the reaction temperature is 119.92 °C. The furfural was obtained from the above xylose extract using carbon -based solid acid catalyst at the second step with the furfural yield up to 15.74%. The experimental results provide theoretical and experimental basis for the high value-added use of walnut nutshell.