Abstract: Numerical simulation and experimental measurement were combined to study the fluid field distribution and particle separation rule. Also,the structure of collecting groove and recoil water hole configuration were optimized. The results show that the hydraulic weir,that exist in the junction of the separation zone and the stratified area,has the effect of strengthening the separation process. The cross section of rifle circle and the arrangement of recoil water holes have a great influence on the separation process. The stratification characteristic of particles was modeled by numerical simulation and the double arc side wall was designed. According to the turbulence intensity,flowing film in the rifle circle can be divided into three layers from top to bottom including a weak turbulent layer,a disturbance transition lay- er and a jet control layer. Pseudo elastic waves caused by jet control layer are short and frequent with a large number of recoil holes,which is suitable for fine particles separation. Pseudo elastic waves are long and sparse with relatively small number of recoil water holes,which is suitable for the separation of coarse particles.