A method and apparatus for supporting multiple IMS networks includes an electronic device supporting multiple IMS networks. A modem receives communication services through an access network and multiple IMS networks including first and second IMS networks; and a communication control module includes a processor. The communication control module is configured to attach the electronic device to the access network on the basis of first identification information corresponding to the access network, register the electronic device in the first IMS network via the access network on the basis of second identification information corresponding to the first IMS network, and register the electronic device in the second IMS network via the access network on the basis of third identification information corresponding to the second IMS network.