To improve the mechanical properties of soil-pile interface and facilitate the construction of the uplift pile in soft clay, a new type of uplift pile with continuous helical grouting-screws has been developed. Based on a series of large-scaled direct shear tests on the unfolded soil-screw interface, numerical method is used to explore how the grouting screw affects the deformation behaviors and failure mechanism. Numerical simulations have illustrated strong dependence of the interface responses on the spacing interval of screws. With respect to non-screw pile-soil interface, the helical screw pile-soil interface produces significantly higher shear resistance. The screwed interface tends to fail in an arc-shaped failure surface whist the traditional non-screw pile produces a thick failure plane between soil and pile. The increasing height of arc tends to result in growing shear resistance of interface. There is an optimal screw spacing interval, at which the maximum soil-pile shear resistance can be activated.