A method and an apparatus for processing a fault in a multi-operator core network are disclosed. The method is applied to a first base station, where multiple operators share a network within coverage of the first base station, and the method includes: acquiring an identifier of a faulty operator, where the faulty operator is an operator whose network is faulty within coverage of the first base station; and notifying UE served by the first base station of the identifier of the faulty operator by using a specified message, so that the UE served by the first base station no longer accesses the network of the faulty operator within coverage of the first base station.