To understand the influence of the excess pore pressure around the pile and at the pile end in layered cohesive soils after pile sinking on the soil compaction effect of pile driving, by using in-situ tests and numerical simulation methods, the spatiotemporal distribution characteristic of the excess pore pressure at the pile-soil interface and the variation law of the overlying vertical effective stress with time were analyzed. On the basis of the hydraulic fracturing theory and the cavity expansion theory, the modified Cam-clay model was introduced to derive the modified formula for calculating the overlying vertical effective stress and excess pore pressure at the pile-soil interface during the consolidation of soil around the pile. The results show that from the point of view of time, the excess pore pressure dissipates with time and the overlying vertical effective stress increases gradually under the external load of the pile top; After 30 days of pile formation, the excess pore pressure has basically dissipated, the overlying vertical effective stress no longer increases, and the foundation soil is in a resting period. From the point of view of space, the excess pore pressure increases with the increase of pile burial depth, and it increases faster in the clay layer with poor permeability; Under different load conditions, the smaller the horizontal distance from the pile center and the vertical distance from the pile end, the greater the excess pore pressure; The maximum excess pore pressure near the pile end and pile center is negatively related to the pile top load.