The impact of ice load will significantly increase the torsional vibration of the propulsion shafting and worsen the working condition of the components of the propulsion shafting. The lumped parameter modeling and boundary conditions are established for the electric propulsion shafting of an icebreaker. The torsional vibration of the traditional propulsion shafting are compared with that of the propulsion shafting under the impact of ice load by using the Newmar k- β time domain method. It shows that the ice load significantly affects the torsional vibration of the shafting, which should be emphasized. In addition, the sensitivity analysis of the torsional vibration of the shafting is carried out for the coupling stiffness and the clutch inertia of the main components of the shafting. The general rules of the influence of the performance of the main components of the shafting on the torsional vibration of the shafting are obtained to guide the design and selection of the shafting equipment. The results can provide guidance for the shafting design of icebreakers.