Abstract: Abstract: The pitch bearing is the key component of the pitch wind turbine. With the increase of the scale of the single machine, the length of the blade continues to increase. Operating in the environment, the repeated working conditions of alternating loads in three directions, axial, radial and overturning moment, are more severe, such as pitting, cracking, surface spalling, and maintenance of the pitch bearing due to insufficient operation and maintenance. Failures such as frame breakage will pose a great threat to the safe operation of wind turbines and cause serious economic losses. Based on the analysis of the failure cause of the pitch bearing of a certain wind turbine, this paper proposes that by rating the operating status of the pitch bearing, the pitch bearing defect can be effectively discovered in advance, and the method of strengthening routine maintenance and early replacement shall be adopted in time to transform the pitch bearing. Maintenance methods, control of maintenance costs and safe operation risks provide a reference for the condition maintenance of wind turbine pitch bearings.