Abstract: Taking the Binhai Port in the old Yellow River Delta as the background, a two-dimensional hydro-sediment model was established to simulate the changes in hydrodynamics and sediment transport due to the port construction. Results indicate the changes of tidal current velocity after the breakwater completion was from −0.8 to 0.5 m/s and concentrated mainly within 15 m isobath near breakwater construction area. The flow velocity at the head of the north breakwater increased significantly. The port area was featured with flow velocity reduction for as much as 0.6 m/s except for the ebb stage of spring tide. The port construction weakened the tidal irregularity as average amplitude of main tidal components was reduced by about 10%. The impact of the port construction on the offshore geomorphic evolution was concentrated within 8 km around the port and within the 16 m isobath areas. The head of the north breakwater was severely eroded, while sediment siltation was distributed mostly at the harbor entrance.