Abstract: The numerical model based on dynamic and sliding mesh technique combined with cavitation model is applied to simulate the hydrodynamic behavior of a ducted propeller running at high rotating velocity in a linear mo-tion on the effects of cavitation，the growth and development of cavitation of the propeller in a linear motion are ob-served，the cavity effects on surrounding flow fields and propeller thrust when the propeller is in a linear motion are investigated，and the influences of different rotating velocities and linear velocities on thrust characteristics of the ducted propeller in cavitation environment are analyzed． Ｒesults indicate that (1) the growth and development of cavitation on the propeller blade and the hydrodynamic behavior variations caused by the cavitation can be simulated objectively with the numerical approach combined with cavitation model when the propeller is at high rotating velo-city; (2) the maximum relative error between numerical and experimental results with cavity effects is smaller than that without cavity effect，the higher the advanced velocity or the rotating velocity is，the more significant the diffe-rence exists between them; (3) the effects of cavitation on the hydrodynamic characteristics are not only confined to suction surface，but also on high pressure blade surface．

Key words: ducted propeller, dynamic mesh, sliding mesh, cavitation, hydrodynamics