Abstract: Based on the long series of measured data about Dalinghe River runoff and underwater terrain, the hydrodynamic numerical model is established to simulate the tidal current of Dalinghe River estuary and the main characteristics of hydrodynamic process in the estuary and northern sea area of Liaodong Bay are discussed considering the influence of tidal current and river runoff. The results show that the ocean current in waters around the estuary is mainly tidal current with obvious reciprocating nature. The general movement trend of tidal current is northeastward at high tide and southwestward at low tide. The speed of spring tide is larger than that of neap tide and the duration of flood current is almost equal to that of ebb current, with the maximum flood speed of 0.52 m/s and maximum ebb speed of 0.4 m/s. The distribution of average tidal current intensity during flood and ebb is roughly consistent with the sea depth contour.