Based on the N-S equation,and the momentum source method,and the VOF method for tracking the free surface,a numerical wave flume is obtained,which can both generate and absorb waves.The wave transmission and wave overtopping of permeable breakwater are numerically simulated by the numerical wave flume.Compared with the experimental data available,the presented numerical wave flume can numerically simulate the wave transmission and wave overtopping of permeable breakwater.