Abstract: In this paper, a dynamic modeling method was carried out for the flow resistance influence analysis of a six-degree-of-freedom (6-DOF) underwater manipulator applied in deep water environment. Considering the influence of fluid resistance, a dynamic model of underwater manipulator was established based on iterative Newton-Euler vector mechanics method and Morison equation. According to the obtained analytical expression of the hydrodynamic moment for the base joint and append mass moment, the driving torque and water resistance moment of the base joint were derived for the 6-DOF manipulator. A simulation test was completed with Matlab software. The results show that, the influence of water resistance on the control moment of the manipulator can rise up to 8.69%, meaning that the influence of water resistance on the manipulator can not be ignored. In some cases of underwater high-precision operation, the application of the proposed 6-DOF underwater manipulator dynamic model, considering the influence of water resistance, can achieve higher control accuracy.