Abstract: In order to study the load deformation and stress distribution of the dualdrive system, a simplified dualdrive elastic cylinder system was researched. Based on the vibration theory of continuous elastic body, the singledimension torsional vibration equation for dualdrive elastic cylinder was set up and its analytic solution was deduced. According to the form of the analytic solution, the odddegree modal responses of cylinder’s deformation and shear stress can be suppressed by reducing the difference between the two input torques. The further numerical simulation results show that the larger the difference between the two input torques with constant sum, the larger the maximum shear stress of the cylinder.