Abstract: To study the influence of soybean dregs powder on the quality of wheat flour, fine pulverization soybean dregs powder was added to 100g wheat flour at 0, 5, 10, 15 and 20g.The methods of a Brabender farinograph, a Brabender extensograph and Scanning electron microscopy technology ( SEM) were adopted to study dough characteristics and observe the microstructure change of the dough. The results showed that with the increasing content of the soybean dregs powder in wheat flour, the flour water absorption, dough development time and dough stability time increasing. In addition, extensibility, extension energy, wet gluten content of the dough decreased, while dough drawing ratio; continuity of gluten ultra structure of the dough was getting worse, the network structure was ruptured.Therefore, addition soybean dregs powder to wheat flour can destroy ultrastruture of gluten.