Abstract: The wind turbine wake has an important impact on the output power of wind farms. In order to study the impact of adding small wind turbines on the overall output of wind farms, OpenFOAM was used to simulate the combination of two large wind turbines and three small wind turbines arranged horizontally between two large wind turbines, and four operating conditions with different distances between small wind turbines and large wind turbines downstream and one of the operating conditions with different heights of small wind turbines as the study object. The layout adds three small wind turbines between two large wind turbines, and each row of small wind turbines has a different distance from the large wind turbines downstream. The results show that when the small wind turbines are set at a height of 37 m, the power of the downstream large wind turbine increases gradually with the increase of the distance from the upstream large wind turbine. When the distance of the small wind turbine from the downstream large wind turbine is fixed, increasing the hub height of the small wind turbine makes the power of the downstream large wind turbine decrease.