The invention discloses a reciprocating-type compressor fault diagnosis method based on multi-sensor information fusion, and the method is characterized by comprising the following steps of 1, collecting data; 2, constructing a fault characteristic sub-space and a fault space; 3, obtaining a fault diagnosis network; 4, acquiring characteristic fusion diagnosis results; and 5, carrying out D-S evidence theory decision-level fusion diagnosis, and giving out a decision-level diagnosis result. The method has the advantages of convenience in application, high diagnosis accuracy and applicability to a production site of reciprocating-type compressors of petroleum chemical industrial enterprises.