［Objective］ This study aims to investigate the mechanism of rain erosion on windturbine blade coating and the influencing factors of rain erosion.［Methods］This study focuses on therainfall characteristics of the operating environment for wind turbine blades. Rain erosion resistancetests were conducted under six different rainfall conditions，by the rotating arm rain erosion test method， while maintaining identical environmental temperature，test speed，and raindrop diameter. Throughanalysis and comparison of the time of coating failure and mass loss under varying rainfall conditions.［Results］ It was observed that coatings in the tip to middle region exhibited different degrees ofbreakdown. The higher of rainfall，the greater the impact on the coating performance. However，the degradation of the coating protective performance exhibited a non-linear relationship with increasingrainfall intensity.［Conclusion］When evaluating the performance of wind turbine blade coatings inactual wind field environments based on laboratory rain erosion test results，the damaging effects of different rainfall intensities on the coatings should be comprehensively considered，and rainfall conditions should be set based on the rainfall environment in wind fields.