The present invention provides an automatic system failure detecting device, which is connected with a monitored system to automatically detect operating state of the monitored system, including equipments and units of optical communication and transmission node system, to report to senior administrators or warn and comprises a configuration unit to receive user configuration information from a communication channel and transmit the information to a control unit, a control unit connected with the configuration unit to dispatch the configuration information to a detecting unit and receive detecting results fed back by the detecting unit, a detecting unit connected with the control unit and a monitored system through a detecting interface to detect hardware state, configuration information, function index and/or performance index of the monitored system, generate the detecting result, feed the detecting result to the control unit, and an output unit communicated with the control unit to output the detecting result sent by the control unit. In addition, the present invention also provides a method to automatically detect system failures with the device above.