In order to study the cavitation characteristics of propellers under oblique flow conditions and quantitatively analyze the blade cavitation area, the present paper takes the PC456 propeller model as the research object. Based on the OpenFOAM platform, the cavitation performance of the PC456 propellers under oblique flow is numerically calculated using the SST k-omega turbulence model and Schner-Sauer cavitation model. It is found that the influence of the oblique flow on the hydrodynamic performance of the propeller cavitation increases with the increase of the oblique angle. Within the phase range of [-90°, 40°], the cavitation area of the blade reaches its maximum at the -20° phase, and as the oblique angle increases, the amplitude of the change in bubble area also increases. In addition, the numerical results of the cavitation area are in good agreement with the experimental values, especially under low cavitation numbers. This proves the effectiveness of the numerical method used in the present research.