. A novel fault diagnosis method for centrifugal compressor was proposed by using entropy- based fuzzy gray relational analysis (EF-GRA). Firstly, the minimize entropy principle (MEP) was used to subdivide all real-valued fault features and construct membership functions of fuzzy variables. Secondly, based on the gray theory, the fuzzy-gray relational coefficients (F-GRC) were calculated and the weighted fuzzy-gray relation degrees (WF-GRD) were obtained, so that the diagnostic result can be determined. Finally, a centrifugal compressor fault dataset was used to illustrate the proposed method, and the results show that it has strong engineering practicability and validity.