Abstract: A conductive roller fractured after running for a period of time. The fracture causes of the conductive roller were analyzed by means of macroscopic observation, chemical composition analysis, hardness test, mechanical property test, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that the fracture property of the roller shaft of the conductive roller was multi-source fatigue fracture. The formation of the fracture source was related to the serious intergranular corrosion at the welding arc of the roller shaft and the roller, and the intergranular corrosion was caused by the strong acidic environment of the conductive roller and the 'sensitization' reaction in the welding heat affected zone.