The reefs at the bottom of the river increase the turbulence of the water,which is conducive to the formation of fish eggs.The river with a large number of reef sections is usually an important place for fish to perch and spawn.Nevertheless,the reefs also have the possibility of impeding navigation.Cleaning up the reefs in the waterway has a certain influence on the turbulence intensity of the water body and changes the habitat of fish.Therefore,it is necessary to fully demonstrate the practice of waterway clear up reefs in important fish habitat sections.Using the turbulence kinetic energy as an index to evaluate the turbulence intensity of water body,the three dimensional numerical simulation of turbulent flow is carried out in the middle reaches of the Xijiang River where are also known as the river section of the rare fish reserve.At the same time,the turbulence kinetic energy of water body and the volume of turbulent water in different intensity are calculated before and after removing the reefs,and the change law and reason are analyzed.The results show that :the turbulent kinetic energy intensity has a positive correlation with the depth of water;the reef cleaning up project causes that the volume of water containing low turbulent kinetic energy increase and the volume of water containing high turbulence kinetic energy decrease;the variation of turbulent kinetic energy in the bottom water body is higher than that in the surface;the change rate of the volume reduction of high turbulent kinetic energy water is greater than that of the increase of the volume of the weak turbulent kinetic energy water.