Considering the effects of phase-change on the bubble interface, a new cavitation model based on Rayleigh-Plesset Equation is given and the secondary cavitation is successfully modeled. Using the new cavitation model on cavitation flow fields of the 2 d steady axisymmetrical hemispherical cylinder, the model surface is alternately distributed by a higher cavity pressure and lower collapse pressure due to the growth and collapse of the secondary cavity. With the decrease of cavitation number, the main cavity gradually becomes larger, and the secondary cavity zone is gradually moving to the tail of the model and falling off.