Based on a practical navigation lock with high-head and large scale in China,we use RNG k-ε model of turbulence flow and combine with VOF method to establish a corresponding 3d numerical model of the filling and emptying system,which is two areas through the ports introducing the water to the chamber from the main culverts designed at the bottom of lock chamber.We simulate the 3d hydraulic characteristics of the normal operation during the filling process,and analyze the flow field within the lock chamber,flow rate distribution of all the side ports and energy dissipation mechanism of ditches placed on the lock chamber bottom.The corresponding technical references from the research achievements can be provided for the design of the filling and emptying system.