Through the combination subject of scientific research, the design method of the winch driven by contactless magnetic coupling is researched for the core purpose of the turning shaft sealing in a deepwater environment. This method has six design phases, including domestic and foreign information query and retrieval, graphic analyses of relevant structures, innovative design of 2D assembly sketches, a theoretical computation of structure parameters, the 3D modeling and motion simulation and engineering drawing. This method is of generality, which can provide examples for the postgraduate students and engineering personnel in self-renovation design of scientific research.