The wake effect seriously reduces the power output of wind turbines. At present, the main method to solve the wake effect is to optimize the wind field layout, which is unrealistic for the wind farms already built. In contrast, yaw control can make the wake offset to reduce the influence of wake effect and improve the generating capacity of the unit. In this paper, two lidar wind meters and SCADA system are used to carry out experiments in a wind field. Based on this, the flow field characteristics at different positions of the unit are analyzed. According to the principle of wake drift, the change of the total power of two turbines under different yaw angles is analyzed. The results show that the total output power of the unit can be effectively increased when the yaw does not exceed 45, with the maximum increase of about 13.5%. It can be seen that although the yaw of the upstream turbine reduces its own power generation, but its wake deviation can effectively improve the output power of the downstream turbine. This scheme can be applied in wind farm..