Abstract: Abstract: Xylanase has attracted extensive attention because of the application potential in feed, food and paper area, capable of degrading hemicellulose which is prevalent in nature. This research is to construct a recombinant engineered bacteria with efficient secretory expression for thermophilic Saccharomonospora viridis xylanase SviXyN10A using molecular biology techniques, and then study the characterization of the gene product expressed in Pichia pastoris. The results indicate that the gene product of Svixyn10A was successfully expressed in Pichia pastoris, showing the highest enzymatic activity of 7.53 IU/mL with methanol induction for 2 days. Recombinant xylanase SviXyN10A showed good activity at wide range of pH effect（pH5.0-9.0）, and the optimum reaction temperature is 70℃, pH7.0. What is more, the xylanase showed excellent thermo-alkali-stability and almost no cellulase activity. Thus, it is a potential candidate for future use in industrial areas particularly in the pulp and paper industry.