Ultrasonic treatment combined with soy protein isolate(SPI) was used to modify and modulate potato flour in order to solve the processing performance defects such as poor dough ductility and instability due to the lack of gluten in potato flour and the inability to form a network structure of dough. The ratio of sulfhydryl to disulfide bond and the SEM observation results were used as the basis for the construction of gluten free dough simulation network. The results showed that ultrasonic treatment had a certain effect on the construction of the simulated network structure of gluten free dough with potato flour， but the effect was not obvious. The synergistic effect of ultrasonic treatment combined with SPI could significantly improve the conversion ability of sulfhydryl and disulfide bonds in the system as shown with significant increase of the ratio of disulfide bond content to free sulfhydryl content increases， The 'opportunities' of forming network structure similar to wheat gluten protein in potato whole flour dough increased， which strengthened the internal structure of potato whole flour dough to a certain extent. Too long ultrasonic time and too high ultrasonic power would cause the formation of disulfide bonds to collapse. The multiple quadratic regression model for constructing the simulated network structure of gluten free dough with potato flour was optimized by response surface method. The gluten free dough simulation network of potato flour was formed evidently through the proper treatment with the addition of 0.94% SPI， the ultrasonic time of 15.19 min， and the ultrasonic power of 500 W， at which the ratio of disulfide bond content to free sulfhydryl content reached optimized value of 0.278， which is 2.53 times to that of 0.11 of controlled group. SEM indicated that the microstructure of potato flour dough with synergistic treatment of ultrasonic and SPI was closer to that of wheat dough. The results showed that ultrasonic treatment combined with SPI could construct the network structure of gluten-free potato flour， which was helpful to improve the processing performance of gluten-free potato flour.