<p>Aiming at the shedding and collapse characteristics of the U-shaped cavity, this paper first accurately simulates the cavitation flow using the modified SST turbulence model and the Sauer cavitation model. On this basis, the effective distance of cavitation erosion in the risk prediction of the U-shaped cavity is studied based on the principle of energy transfer. Furthermore, the development process and the characteristics of cavitation erosion risk of the U-shaped cavity are analyzed. It is found that the vapor phase volume fraction near the surface at the location of the cloud cavity is smaller due to the effect of the re-entrant jet, and when the recognition radius is too small, it cannot fully reflect the volume change process of the cavity collapse near the surface. The cavitation erosion risk caused by the U-shaped cavity at the trailing edge is significantly higher than that corresponding to the cloud cavity. When the number of layers of extracted nodes is too large, exceeding the effective distance of cavitation erosion for the cavitation bubble collapse, the cavitation erosion risk of the cavity at bottom corners of both legs before the U-shaped cavity reaches the trailing edge will be over-predicted. The cavitation erosion risk mainly comes from the collapse of the shed cavity before the complete creation of the U-shaped cavity. In addition, the front end of the shed cavity has a higher risk. The U-shaped cavity mainly causes cavitation erosion near the trailing edge.</p>