In ocean engineering, large-diameter steel pipe piles are commonly used as foundations, and they are often installed using either hammer driving or static pressing methods.In cohesive soil foundations, the soil displacement and heave caused by the pile driving effect weaken the shear strength of the surrounding soil and generate excess pore pressure. After pile installation, the excess pore pressure around the pile gradually dissipates, and the soil undergoes reconsolidation, with its strength and stress state gradually recovering. However, existing studies and design codes rarely consider the effects of pile driving and consolidation on the bearing performance of horizontally loaded piles.This study uses a self-developed multi-stage Euler-Lagrange method to continuously and comprehensively simulate three distinct stages of static-pressed pile installation: pile penetration, consolidation strengthening, and horizontal loading. The research delves into the pile-soil interaction mechanism, the soil strength recovery mechanism between piles, the ultimate resistance of the soil around the pile, and the variation of the P-y curve. The results show that while the consolidation effect does not change the soil deformation mechanism, it significantly increases the ultimate soil resistance along the pile side. Furthermore, the study clearly identifies and quantifies the effects of pile driving and consolidation on the bearing capacity of horizontally loaded piles, establishing a model for the growth ratio of ultimate soil resistance with depth, and proposing a P-y curve that incorporates both pile driving and consolidation effects. The research findings have significant theoretical value and practical implications for optimizing the calculation methods for the static bearing capacity of marine pile foundations.