The invention discloses a system fault diagnosis method. The system fault diagnosis method comprises the following steps of acquiring fault attributes of a diagnosed software system through a networkmanagement system, conducting matching in a preset rule database according to the fault attributes, and generating a fault diagnosis decision list according to the matching degree of the fault attributes and the preset rule database; when the fault attribute is unsuccessfully matched with a preset rule database, sending the fault attribute to a fault analysis and rule development end for analysis;and receiving a new processing rule obtained by analyzing unsuccessfully matched fault attributes by the fault analysis and rule development end, and merging the new processing rule into the rule database.