The invention discloses a method and a system for determining risk degree of protective devices. The method includes: determining fault modes which can be monitored by an information protection systemused for real-time acquisition of operating data of the protective device; determining information of all abnormal statuses of the protective device in the operating data according to the operating data of the protective device acquired by the information protection system; determining the fault mode of each abnormal status information; and determining risk degree of the protective device according to influence degree of the fault mode of each abnormal status information on the protective device and the protection system. The method and system for determining risk degree of the protective device provided by the invention can complete an on-line forecast to the risk degree of the protective device accurately and automatically, and has characteristics of saving manpower and strong reliability.