Abstract: Taking GE 2.5 MW wind turbine as the object, aiming at the fatigue wear problem of key components of GE wind turbine yaw damping system under long-term alternating load, a wear resistance and life evaluation method based on fatigue test is proposed. By establishing the vibration equation of rotating elastic body to quantify the wear behavior under dynamic conditions, the piecewise function model of wear volume fatigue damage stage is innovatively constructed, and the life prediction is realized by coupling Miner linear cumulative damage criterion. The experimental results show that the maximum amplitude of braking friction fluctuation evaluated by this method is 570 N, the maximum time is 39 ms, and there is a deviation of 1 ms from the index, which provides a theoretical basis for the design optimization and state operation and maintenance of yaw damping system.