A two-phase mixture model based on the solution for the Navier-Stokes equations has been utilized in calculating the hydrodynamic characteristics of cavitating honeycomb grid fins with different configurations.The calculation results of lift, drag, and hinge moment coefficients are presented in various cavitation numbers and angles of attack, and its hydrodynamic features are also analyzed.The calculation results indicate that cavitation will reduce the lift/drag ratio of grid fins.The increment of horizontal blades as lift surface cannot unendingly improve lift because of the disturbance between the blades.