Abstract: Based on the purpose of improving the soluble expression of β-xylosidase(Xln-DT) from Dictyoglomus thermophilum, six commercial chaperone proteins were screened by co-expression of chaperone proteins. The results showed that the soluble expression of Xln-DT was increased to 1.31 times of initial expression of proenzyme after the co-expression system of inducible plasmid pG-KJE8 and recombinant expression plasmid pet-28a-xln-DT containing xln-DT gene were constructed. The terrific-broth medium was induced by adding 0.01 mmol/L isopropylthio-β-D-galactoside(IPTG), 5 μg/L tetracycline, 1.5 g/L L-arabinose with 2.0% glycerol and 1.2% peptone as carbon and nitrogen sources, respectively. Finally, enzyme activity of Xln-DTwas 11.9 U/mL at 32℃ for 60 h, which was 4.22 times higher than thatof the original enzyme in LB medium. In addition, the process and enzymatic mode of 5 kinds of xylan with endoxylanase XynB-DT and β-xylosidase Xln-DT were investigated. After adding Xln-DT, the enzymatic hydrolysis yield of fivekinds of xylans (beechwood xylan, birchwood xylan, corncob xylan, oat xylan and bagasse xylan) were 84.4%, 90.2%, 79.6%, 77.3% and 64.7%, respectively, which was significantly improved compared with that only adding XynB-DT. All the results could not only significantly improve the soluble expression of Xln-DT, but also had a good application prospect in the production of xylooligosaccharides and xylose by enzymatic hydrolysis of xylan.