Abstract: Three different models, k-ω, DES and LES, are conducted in the analysis of the tip vortex flow field. In order to reduce the discrete error induced by the grid, mesh refinement is applied to the area of the tip vortex core in numerical simulations. The axis and tangential velocities of the tip vortex flow field with no cavitation are calculated, and the calculated velocities agree well with the experimental results. On the basis of this process, the influence of vortex roll-up on the tip vortex pressure filed is discussed, and bubble static equilibrium is proposed by which the tip vortex cavitation inception number is computed.