Abstract: The technology of fault diagnosis and prediction develops a new way for the reliability and safety of complicated equipment system.The fault diagnosis and prediction is a difficult problem due to the complex structure of chemical equipment,the uniqueness of operating environment and the presence of multi-sources of faults. Grey prediction theory is discussed for diagnosing and forecasting conditions on continuous stirred-tank reactor and dimethylmethane gas compressor.The field example examination and the modeling process are presented. We calculate with GM(1,1) for chemical equipment,and the results show that the forecast model is simple and reliable.Using this method, one can make sure of the fault developing tendency and judge dangers to the equipment,and thus guide to make a decision if the equipment should be stopped.