Abstract: In order to increase the overall power of wind farm without increasing the unit load, a cooperative control method based on active variable pitch is proposed in this paper. In this method, pitch angle is used as the control variable of cooperative control. The analytical wake model is used to simulate the flow field in a wind farm in real time. Differential evolution algorithm is used to optimize the optimum pitch angle of plant units. In a dynamic wind environment with an average wind speed of 8 m/s and turbulence intensity of 8%, the simulation shows that compared with the traditional single-unit optimal control strategy, the cooperative control method based on active pitch variation can increase the overall power generation of a wind farm with three units in tandem by more than 10%, while significantly reducing blade load. The research results fully show that the wind farm cooperative control method based on active variable pitch has certain practical application value.