The GIS was widely used to prevent accidents that may occur during transmission and distribution. The circuit breaker, disconnecting switch and earthing switch were operated using a mechanism. Among the components operating with a mechanism, the Line earthing switch(LES) must operate under high speed at a desired point. A damper system capable of absorbing high kinetic energy is needed in a mechanism. In this study, the parameters to affect the performance of damper system were analyzed and the design variables were defined. The design of damper system is simplified by minimizing design variables. The damper system was evaluated according to dynamic analysis and fluid analysis, and the performance of the damper system was verified by experiment.