The invention provides a reliability evaluation method and device for wide-area protection system fault component identification and solves the technical problem that the current reliability evaluation of the wide-area protection system is not specific to a specific protection algorithm, only takes account of the failure and the repair process of a single device, can only reflect the availabilityof system structure, and cannot really describe the principle and the failure process of a function. The method provided by the present invention includes: S1, acquiring the information acceptance rate d of a wide-area monitoring center in the wide-area protection system; S2, acquiring the theoretical quantity Q0 of the power direction information uploaded by all suspected fault components in a fault area A to the wide-area monitoring center; S3, in combination with the information acceptance rate d and the theoretical quantity Q0 of the power direction information uploaded by all suspected fault components in the fault area A to the wide-area monitoring center, calculating a correct rate of identifying the fault components in the fault area A.