Abstract: In order to study the effect of different turbulence intensities on the velocity distributions and turbulent characteristics and arrange the multi-unit array reasonably, two wake characteristics at different turbulence intensities were experimental studied for a model tidal turbine. The results indicate that the turbulence intensity and mean velocity distribution of the model tidal turbine are symmetric in the transverse direction. The maximum velocity deficit is at near the tip of model tidal turbine at 1.5 D. The mean velocity distributions above the hub are similar at 1.5 D in the streamwise direction at different turbulence intensities. At 10 D after the center of the turbine, the velocity at low turbulence intensity can recover to 89.60%, while the velocity at high turbulence intensity can recover to 95.22%, the rate of velocity recovery at high turbulence intensity is much higher because it can improve the velocity pulsation characteristics at the whole flow field. The results have a significant significance for multi-unit array arrangement.