A method for downloading in a ubiquitous network by means of multicast, comprising: a) after requesting to download a media service, acquiring, by a terminal from a tracing server, an address of a cache server corresponding to the media service, and requesting the cache server to transmit the media service; characterized in that the method further comprises the steps of: b) after receiving the request, triggering, by the cache server, a context server to determine, according to a preset multicast terminal threshold value, whether a condition for triggering multicast is met; c) when the condition for triggering multicast is met, cooperating, by the cache server, with the context server and a joint radio resource management server to determine a plurality of terminals participating in multicast and a multicast channel; and d) sending, by the cache server, data of the media service to each terminal on the multicast channel via a resource control node; and in that step c) further comprises: c1) when the condition for triggering multicast is met, determining, by the cache server according to the multicast terminal threshold value, the plurality of terminals participating in multicast from surrounding terminals of the terminal, acquiring, from the context server, network context information of the plurality of terminals participating in multicast; and c2) determining, by the joint radio resource management server according to the network context information sent from the cache server, the multicast channel, and sending the multicast channel to the cache server, the network context information comprises: resource control node channel information corresponding to the plurality of terminals participating in multicast, network load conditions and network signal strength, the resource control node channel information comprising all available channels and parameter information of the channels for the plurality of terminals participating in multicast to access the resource control node. a) after requesting to download a media service, acquiring, by a terminal from a tracing server, an address of a cache server corresponding to the media service, and requesting the cache server to transmit the media service; b) after receiving the request, triggering, by the cache server, a context server to determine, according to a preset multicast terminal threshold value, whether a condition for triggering multicast is met; c) when the condition for triggering multicast is met, cooperating, by the cache server, with the context server and a joint radio resource management server to determine a plurality of terminals participating in multicast and a multicast channel; and d) sending, by the cache server, data of the media service to each terminal on the multicast channel via a resource control node; c1) when the condition for triggering multicast is met, determining, by the cache server according to the multicast terminal threshold value, the plurality of terminals participating in multicast from surrounding terminals of the terminal, acquiring, from the context server, network context information of the plurality of terminals participating in multicast; and c2) determining, by the joint radio resource management server according to the network context information sent from the cache server, the multicast channel, and sending the multicast channel to the cache server, the network context information comprises: resource control node channel information corresponding to the plurality of terminals participating in multicast, network load conditions and network signal strength, the resource control node channel information comprising all available channels and parameter information of the channels for the plurality of terminals participating in multicast to access the resource control node.