Abstract: To improve the utilization of soybean dregs with the flavor and taste,and expand the application of soybean dregs in the food field,the soybean dregs was used as the main raw materialto be extruded after mixed with low-gluten flour.The contents of soluble dietary fiber was used as an index. The extrusion was optimized by response surface method.The functional groups and particle size of combination was analyzed by fourier transform infrared spectroscopy and grain size analyzer.The stability analysis was carried out by differential calorimetry scanning. The results showed that the optimum extrusion processing parameters were water content 30%,extrusion temperature 180℃,screw speed 160 r/min. At this time,the soluble dietary fiber contents of the combination increased from 3.11% to 15.47%.The water holding capacity of the combination after extrusion was increased from 3.45 g/g to 4.86 g/g,while the oil holding capacity was from 2.27 g/g to 4.85 g/g. The dietary fiber in the compound powder after extrusion had a significant absorption peak of saccharide characteristics. The grain size of soluble dietary fiber in the compound powder after extrusion was reduced. The combination had a high thermal stability after extrusion. In summary,the physicochemical properties of the combination after extrusion were significantly improved,which provided a theoretical basis for the modification and utilization of soybean dregs.