Abstract: The presence of non-metallic inclusions in bearing steel severely shortened the service life of parts. The causes of cracking and steel ball peeling in the inner ring of GCr15 bearing steel were analyzed using macroscopic observation, metallographic examination, hardness testing, scanning electron microscopy and energy spectrum analysis. The influence mechanism of non-metallic inclusions on the mechanical properties and fatigue life of parts was elucidated. The results show that in certain specific cases, non-metallic inclusions in bearing steel could refine grain size and improve the impact performance of the steel. However, in most cases, discontinuous low-strength non-metallic inclusions could damage the performance of the steel, reduce its mechanical properties, and shorten its fatigue life. Non-metallic inclusions in bearing steel could be removed using physical and chemical methods.