In recently years, the problem of pile sinking adjacent to slope often happen in the practice and initiates many engineering accidents. Due to the non-axisymmetric characteristics of pile sinking boundary conditions, it is difficult to solve this problem by theoretical solution. The paper used the two-dimensional particle flow code (PFC2D) of discrete element method to analyze the slope squeezing displacement under pile sinking adjacent to slope in the process of pile sinking, which can overcome the macroscopic continuity hypothesis of traditional continuum mechanics model. The results show that the influence scope of slope squeezing displacement is more and more larger with the constantly pile sinking, and the squeezing displacement mode of slope also gradually changes; soil adjacent to the pile body and pile terminals produces downward displacement under the combined action of radial extrusion of pile and its side friction, the squeezing displacement of the soil in a certain distance away from the pile body produces vertical uplift displacements under the influence of soil surface and inclined free boundary; the subsequent pile sinking has little influences on slope squeezing displacement when the pile sink to the area below the slope bottom.