In order to increase gel strength,glycosylation modified processing through adding D(+)xylose and xanthan gum to the soy protein isolate was applied.The glycosylation modification conditions were optimized by Central composite design.The gel strength of the complexes under various conditions were identified and analyzed.The results showed the optimum reaction conditions were: reaction temperature 87.27℃,reaction time 40 min,the glycosylation was 3.9%,sugar gel ratio was 2.81∶1.The gel strength could achieve 91.35g,78% more than unmodified soy protein isolate.The experiment proves that the modification technology can be effectively and significantly improve the soy protein isolate gel strength.