Success of rescue process is determined by reliability and safety of rescue device. Virtual prototype technology is introduced into the dynamics simulation and optimization for the design of an operating mechanism for loading deep submergence rescue vehicle, and the 3D CAD software, multibody system dynamics analysis software were combined. Taking into account wave excitation input at sea state 5 and 8 as the extreme marine working conditions, the virtual prototyping model of the operating mechanism is built by ADAMS. The whole topology relations of the vehicle are defined. Dynamics characteristics of key parts are analyzed in various virtual environments, which is quite difficult to be realized by physical tank test. Optimization strategy is proposed and verified by increasing the number of horizontal wheels and adding gap between horizontal wheels and the track. This method offers a new way to study the innovative design of similar marine special mechanism.