The high temperature and abnormal vibration situation appears continuously in the process of operation for a Sullair air compressor,which brings serious security risks to the cigarette manufacturing.The causes of the compressor abnormal operation were investigated by using the thermal imager,vibration and oil analysis technology.Result shows that oil deteroration is the direct cause of abnormal operation,and the oil monitoring technology is one of the effective means by which enterprises carry out the equipment condition monitoring and fault root cause analysis.