Abstract: Disaster monitoring equipment beyond scope of monitoring in high speed railway disaster monitoring system is a terrible fault which has significant influence on the system at present. Based on the investigation of all disaster monitoring systems that were in use, equipment faults were analyzed by classification, and failure causes were detail analyzed. The results show that during the period from January 2013 to May 2017, there were 54 times of large-scale fault and 184 times of local fault which was site monitoring equipment beyond scope of monitoring. Sensor failure and network failure were the main causes, both accounted for 38% of the total fault causes, followed by the failure of power supply and lightning protection module. In the end, the improvement measures and suggestions were proposed from the aspects of the system management, hardware, software maintenance and emergency disposal which would be used for reference to optimize the construction and maintenance of the disaster monitoring system.