Vibration problem in a wind turbine structure is very important issue in terms of structural stability and power generation performance. In this study, a vibration absorber for a small wind turbine is designed using an equivalent vibration system. First, a 1-degree-of-freedom equivalent vibration system is constructed to have the same resonance characteristics as a small wind turbine. A vibration absorber is attached to this equivalent vibration system and frequency response analysis is performed. Finally, the vibration reduction effect according to the specifications of the vibration absorber is simulated. The purpose of this study is to design a good vibration absorber at the design stage of a wind turbine structure.