To investigate the hydrodynamic characteristics of pile groups in high-pile wharf foundations, this study conducted three-dimensional numerical simulation of the turbulent flow field around a 3×3 pile group array with incoming flow velocities ranging from 0.25 m/s to 1.50 m/s by using Flow-3D software. The results indicate that high-velocity zones form on both sides of the piles, and the extent of these zones tends to expand as the incoming flow velocity increases. The recirculation zone behind the upstream pile is larger, while the recirculation zones behind the midstream and downstream piles are similar in size and smaller than that of the upstream pile. As the incoming flow velocity increases, the shear force and fluid force increase non-linearly. The upstream pile experiences the greatest force, followed by the downstream pile, with the midstream pile experiencing the least force. Additionally, the vorticity in the core region of the wake vortex increases with higher incoming flow velocity. The wake vortex intensity behind the midstream and downstream piles is significantly weaker than that behind the upstream pile, with the wake vortex length remaining stable for the midstream and downstream piles. As the incoming flow velocity increases, the vortex intensity significantly increases, and the vortex structures between the upstream and downstream piles become entangled. These findings are significant for understanding the hydrodynamic characteristics of flow around pile groups and provide valuable reference for engineering design and practical applications.