A wind-tunnel experimental study was performed to investigate the impact of the surge and sway motions of a wind turbine model on the power output, rotor thrust and wake characteristics. A wind turbine model was mounted on a translation platform to simulate the surge and sway motions under given amplitude and frequency. The power output and rotor thrust of the turbine model subjected to surge and sway motions were measured by using a DC variable electronic load and a six-component force sensor, respectively. For comparison, these measurements were also performed in a bottom-fixed wind turbine. The results show that the mean power output and mean rotor thrust of the turbine model under surge and sway motions are almost the same as those of the bottom-fixed turbine. However, the thrust fluctuation amplitude of the turbine model under surge motion is significantly higher than those of the turbine model under sway motion and the bottom-fixed turbine. In addition, the wake characteristics of the turbine model were also investigated by using a particle image velocimetry system. The results show that the surge and sway motions have slight effect on the near and intermediate wake of the turbine model in the horizontal plane at the rotor hub height.