The influence of prefabricated vertical drain (PVD)-enhancing soft soil on the adjacent bridge pile foundation is not sufficiently clear. The related studies are scarce and far behind the requirement of engineering practice. Three-dimensional finite element model (3D FEM) is established to investigate this important issue. Plastic drainage boards in the PVD are modelled by a user-defined element, which considers the axial force and permeability of the plastic drainage board, whereas its weight, shear, and torsion are not considered. The elastoplastic-consolidation coupled model is used for the soils. Field measured results of pore water pressure, ground settlement, and pile cap displacement are used to validate the 3D FEM with good accuracy. A number of useful conclusions can provide guidelines for similar projects and inform designers of the adverse effects of PVD-enhancing soft soil ground on the adjacent bridge pile foundation.