This paper investigates the adverse impacts associated with new wharf piles constructed within a sloping breakwater in close proximity to existing wharf structures during port expansion projects under conditions of deep soft soil deposits and significant water depth.Taking the Sabah Port expansion project in Malaysia as a case study,a representative critical cross-section is selected,and a detailed finite element model is built by Plaxis software.Analyzing the influence mechanism of sloping breakwater construction on pile foundations and exploring optimized control measures is focused on.Comparative analysis of two primary construction schemes reveals that the timing of pile installation is crucial for the new wharf piles.Constructing the piles after the breakwater fill placement is complete and has undergone a certain period of consolidation significantly reduces pile bending moments and horizontal displacements.The effect of construction intervals during breakwater filling is also examined.Through comparative research,a 45-day interval is confirmed as a preferable duration,effectively balancing project schedule demands with minimizing adverse effects on the piles.Furthermore,research on the dredging scheme near the existing wharf indicates that controlling the dredging depth（8 m）effectively balances the stability of the dredged trench itself with the impact on the adjacent existing structure.The findings provide valuable insights for constructing sloping breakwaters near existing structures.By controlling the pile installation timing,implementing construction intervals,and regulating dredging depth,the safety of both new and existing pile foundations can be effectively ensured,while also controlling project costs.