Abstract: With the trend of large-scale development of variable pitch variable speed wind turbine blades,the problem of ultimate load caused by peak thrust is becoming increasingly prominent when wind turbines operate in the rated wind speed range. Therefore,this paper proposes a dynamic thrust reduction control strategy based on the Kalman filtering algorithm on the basis of basic control strategy for wind turbines. According to the energy transfer relationship of the wind turbine,the hub wind speed is estimated by measuring torque,pitch angle,and rotor speed as inputs. The optimal pitch angle of the thrust reduction controller is calculated to achieve dynamic pitch control,in order to reduce the overall axial thrust level of the wind turbine;Finally,taking a 5.0 MW wind turbine as an example,a hardware in the loop simulation experimental platform is built to experimentally verify the proposed control strategy. The experimental results show that this control strategy can effectively reduce the axial thrust of wind turbines and the ultimate load of wind turbines.