Slit type bucket is one kind of flip bucket for energy dissipation generally used in the hydraulic project.In this paper the atomized flow produced behind this energy dissipator is analyzed, a numerical model for the aerated jet considering air entrainment and air resistance force is suggested, and simulation of the rain resulted by the atomized flow is also discussed.Furthermore, the prototype observation data for the atomized flow of Dongjiang Hydropower Station is used to verify the model suggested.