Abstract: This paper takes the interaction between the screw rods that are the driving part of spiral-drive advancing machine and soil in the driving process in silty clay as research background and select three different parameters that affect the tensile of screw rods for the model test.Resultsshow that the order of affect factors is the thread root distance > thread angle > tooth depth. An optimal group of structural features factors was concluded. Finally, regression equations between tension and screw rod structure parameters were obtained by using regression analysis.