Abstract: To address the problem that ship propellers are prone to entanglement by foreign objects such as fishing nets, and that manual removal entails high risks, this study takes a multi-degree-of-freedom underwater entanglement-removal manipulator as the research object. A kinematic model was constructed using the Modified-DH method, and both forward and inverse kinematic solutions were derived. The Monte Carlo method was used to simulate and analyze its reachable workspace. Trajectory planning was performed using polynomial interpolation, and trajectory simulation was implemented using MATLAB. Additionally, Adams was utilized to verify the motion of the virtual prototype. The results indicate that the manipulator has sufficient working space to cover the propeller de-entanglement operation area; the trajectory planned using fifth-order polynomial interpolation exhibits smooth, continuous characteristics, with joint movements free of impacts or abrupt changes, demonstrating good operational stability. These findings provide theoretical support for the structural optimization and control strategy design of underwater de-entanglement manipulators.