Abstract: The inner flow field of hydrocyclone plays an essential role for the separation of a given particle group.The development of internal flow field and the research status of flow field characteristics for hydrocyclone are reviewed.The application of numerical simulation in the establish of hydrocyclone mathematical model,characterization of internal flow field,separation process of solid particles,and optimization design of structural parameters for hydrocyclones are introduced in detailed.Based on these analysis,further investigation on the features of the envelope of zero vertical velocity（LZVV) and an air core will be required.The influence of particle shape,as well as the particle-particle,particle-fluid,and particle-wall interactions on the separation efficiency in high concentration slurry will be the focused on.

Key words: Hydrocyclone, Flow Field, Numerical simulation, Separation