Abstract: To address the issues of low flipping efficiency and poor motion stability in existing flipping tooling during heavy-duty workpiece handling, this paper designs a novel rotary mechanism driven by a worm gear drive. By establishing the kinematic and dynamic models of the mechanism, the influence laws of key parameters on the flipping performance were analyzed, and the multi-objective optimization algorithm was adopted to optimize the parameters of the rotary mechanism. The simulation and experimental results show that the optimized rotary mechanism, while ensuring the flipping accuracy, increases the flipping efficiency by 23% and significantly improves the smoothness of the motion, providing an effective solution for the flipping operation of heavy-duty workpieces.