The invention belongs to the xylose production field and in particular relates to a method for preparing xylose through hemicellulose continuous hydrolysis. The method comprises the following steps: taking a hemicellulose-containing material, smashing, then enabling the smashed material and water to enter a nano emulsifying machine at the same time, continuously preparing aqueous emulsion, then continuously entering a high-shear emulsifying machine with an acid catalyst, and emulsifying, so that stable emulsion is formed; pumping into a continuous tubular reactor by virtue of a pump, and carrying out hydrolysis, so that xylose hydrolysate is obtained, wherein the conversion rate reaches 85-95%; separating out unreacted hemicellulose, separating with solid acid together by adopting a centrifugal machine, and returning to an emulsification working procedure; if filtration clear liquid is sulfuric acid or hydrochloric acid, carrying out neutralization, so that the aqueous solution containing 5-12% of xylose is obtained, wherein the obtained aqueous solution can be directly used for preparing furfural; or carrying out impurity removal, decolorization, desalination, concentration and crystallization by adopting an existing membrane treatment patent technology, so that refined xylose is obtained. The method provided by the invention has the advantages that the sources of the raw materials are abundant, preparation processes are continuous and automatic, high-efficiency production is achieved, and the xylose conversion rate is high.