Abstract: In view of the cracking and failure of the cylinder in a rotary kiln during the shutdown and renovation, the cracked cylinder was sampled by means of macro and micro morphology observation, chemical composition analysis,mechanical property test, metallographic structure analysis, fluorescence detection and XRD analysis, and the reasons for the cracking and failure of the cylinder were summarized. The results show that the local corrosion of the inner wall of the cylinder by corrosive substances in the kiln is the main reason for the microcrack caused by the thinning of the inner wall of the cylinder. The banded structure formed by S and P elements in the base material near the kiln head is prone to deform under stress, which is an important reason for the deterioration of material properties. The low temperature environment increases the brittleness of the cylinder material significantly and promotes the brittle fracture of the cylinder.