The wall culvert side port filling and emptying system is widely used in medium-head ship locks，thus it is of great significance to study the hydrodynamic characteristics of side ports for improving the flow conditions in lock chamber.In this paper,a three-dimensional turbulent numerical model of the ship lock with wall culvert side port filling and emptying system was established.Dynamic grid technology and user-defined secondary development (UDF) were used to simulate the opening process of plane water delivery valves.The numerical model was verified by the water level in lock chamber and discharge measured in physical model tests.The flow pattern,velocity and discharge distribution of side-orifices in filling process with water transfer time were analyzed.The results showed that the velocity,discharge and the jet length of side-orifice increased first and then decreased with water delivery time,and the difference of velocity between upstream and downstream side-orifices decreased first and then increased.