The invention discloses an online fault diagnosis, health analysis and failure prediction system and an online fault diagnosis, health analysis and failure prediction method for servers. The online fault diagnosis, health analysis and failure prediction system for the servers comprises a monitored object unit, a parameter monitoring module, a data analysis module, a parameter statistics module, a system identification module and a result reporting module. The online fault diagnosis, health analysis and failure prediction system and the online fault diagnosis, health analysis and failure prediction method have the advantages that parameters of the servers, network equipment and the like are monitored and are used as equipment health degree indexes, models of load and health degrees of the servers and the network equipment in normal states are identified by the aid of an expert system on the basis of neural network technologies, whether the health degrees of the servers and the network equipment are matched with expected values or not after the servers and the network equipment run under the conditions of certain load levels for a long time can be diagnosed, accordingly, sudden collapse of the servers can be predicted, warning effects can be realized in advance, and the stability of the online fault diagnosis, health analysis and failure prediction system can be improved; the online fault diagnosis, health analysis and failure prediction system is provided with development interfaces, so that takeover functions can be provided for other equipment in later periods.