Abstract: Inner cone hydrocyclone ( ICH) is a new type of hydrocyclone with a reversed inner cone structure main- ly used in liquid-liquid separation at present． To investigate the feasibility of ICH for particle classification，Rey- nolds stress turbulence model and Eulerian two-fluid model (RSM + TFM) were coupled to construct the flow field with gas-liquid-solid phase of ICH and conventional hydrocyclone． The comparative analysis was conducted from the aspects of pressure drop，velocity distribution，particle motion behavior，and separation efficiency． Model valida- tion result shows that the CFD numerical model constructed in this study is consistent with relevant experiment re- sult，and that its prediction on tangential velocity，axial velocity，separation efficiency is reliable． The simulation results indicates that，compared with conventional hydrocyclone，ICH has a lower pressure drop，which can help to reduce the energy consumption of the separation operation，but also leads to a weaker centrifugal force field． In ad- dition，ICH has a better separation effect on coarse particles，and the refined production from the over flow is of higher quality． However，the recovery ability of ICH for fine particles is poor，which results in a larger fine particle loss from the underflow．

Key words: inner cone hydrocyclone, flow field characteristics, computational fluid dynamics, multi-phase flow, numerical simulation, particle classification