The embodiment of the invention discloses a method for realizing multicast communication, which comprises an entry provider edge (PE) router receives multicast data; the entry PE router determines exit PE routers matching with the multicast data in accordance with the multicast addresses of the multicast data and the corresponding relations of the multicast addresses and the corresponding exit PErouters, wherein the correlation relations are set up in the entry PE router; and the entry PE router packages the multicast data by use of the addresses of the determined exit PE routers, and sends the packed multicast data to the determined exit PE routers through an intermediate transmission network in unicast way. The embodiment of the invention also discloses a device for realizing multicastcommunication. The method and the device provided in the embodiment of the invention can realize multicast communication by using multicast transition technology when the intermediate transmission network does not support multicast protocols, so as to dispense with the need for a large number of routers in the intermediate transmission network all supporting the multicast protocols, thereby reducing implementation cost.