A method for implementing point-to-multipoint multicast, wherein a multicast source communicates with multicast receivers by using a network running mLDP and a network running RSVP, wherein: the network running RSVP comprises a network-side root node and network-side leaf nodes, the network-side root node is a PE node that is in the network running RSVP and is oriented to the multicast source, the network-side leaf nodes are PE nodes that are in the network running RSVP and are oriented to the multicast receivers, the network-side root node communicates with the multicast source by using the network running mLDP, and the network-side leaf nodes communicate with the multicast receivers by using the network running mLDP; and the network running mLDP comprises a user-side root node and user-side leaf nodes, the user-side root node is a PE node that is in the network running mLDP and is oriented to the multicast source, and the user-side leaf nodes are PE nodes that are in the network running mLDP and are oriented to the multicast receivers; and the method comprises: receiving, by the network-side root node, an mLDP mapping message, which is sent by a user-side leaf node and forwarded by at least one network-side leaf node, wherein the mLDP mapping message comprises Forwarding Equivalence Class, FEC, information and an mLDP label of the user-side leaf node that sends the mLDP mapping message; acquiring, by the network-side root node, from the mLDP mapping message, the FEC information and the mLDP label of the user-side leaf node that sends the mLDP mapping message; acquiring, by the network-side root node, a Resource Reservation Protocol point-to-multipoint path RSVP P2MP LSP according to the user-side leaf node that sends the mLDP mapping message; allocating, by the network-side root node, a label of FEC information to the FEC information, and sending the label of the FEC information to all the network-side leaf nodes that are on the RSVP P2MP LSP and forward the mLDP mapping message; generating, by the network-side root node, a packet forwarding entry of the network-side root node according to an mLDP label in the 1 st mLDP mapping message received by the network-side root node, the RSVP P2MP LSP, and the label of the FEC information; and characterised by forwarding, by the network-side root node, the 1 st mLDP mapping message among received mLDP mapping messages that belong to the same FEC information, to the user-side root node. receiving, by the network-side root node, an mLDP mapping message, which is sent by a user-side leaf node and forwarded by at least one network-side leaf node, wherein the mLDP mapping message comprises Forwarding Equivalence Class, FEC, information and an mLDP label of the user-side leaf node that sends the mLDP mapping message; acquiring, by the network-side root node, from the mLDP mapping message, the FEC information and the mLDP label of the user-side leaf node that sends the mLDP mapping message; acquiring, by the network-side root node, a Resource Reservation Protocol point-to-multipoint path RSVP P2MP LSP according to the user-side leaf node that sends the mLDP mapping message; allocating, by the network-side root node, a label of FEC information to the FEC information, and sending the label of the FEC information to all the network-side leaf nodes that are on the RSVP P2MP LSP and forward the mLDP mapping message; generating, by the network-side root node, a packet forwarding entry of the network-side root node according to an mLDP label in the 1 st mLDP mapping message received by the network-side root node, the RSVP P2MP LSP, and the label of the FEC information; and characterised by forwarding, by the network-side root node, the 1 st mLDP mapping message among received mLDP mapping messages that belong to the same FEC information, to the user-side root node.