A method for protecting a multicast traffic, comprising: setting up a backup path for a working path that needs to be protected, and pre-storing route information of the backup path in an entry of a route table; switching, by an upstream node of the failed path, a multicast traffic from the working path to the backup path when a failure of the working path is detected; the method further comprises: receiving, by the upstream node, a first traffic request from a downstream node through another normal path; replicating, by the upstream node, the multicast traffic to the another normal path without stopping sending the multicast traffic to the backup path so that the downstream node receives two copies of the multicast traffic; receiving, by the upstream node, a first prune packet from the downstream node through the backup path and stopping sending the multicast traffic to the backup path; receiving, by the upstream node, a second traffic request from the downstream node through the working path after the working path restored; replicating, by the upstream node, the multicast traffic to the restored working path without stopping sending the multicast traffic to the another normal path; receiving, by the upstream node, a second prune packet from the another normal path and stopping sending the multicast traffic to the another normal path; wherein the setting up the backup path for the working path that needs to be protected, further comprises: designating a backup egress port as an egress port of a current node; designating a backup ingress port as an ingress port of a downstream node of the current node; and storing the backup egress port and the backup ingress port in the route information, wherein a path between the backup egress port and the backup ingress port is the backup path. setting up a backup path for a working path that needs to be protected, and pre-storing route information of the backup path in an entry of a route table; switching, by an upstream node of the failed path, a multicast traffic from the working path to the backup path when a failure of the working path is detected; the method further comprises: receiving, by the upstream node, a first traffic request from a downstream node through another normal path; replicating, by the upstream node, the multicast traffic to the another normal path without stopping sending the multicast traffic to the backup path so that the downstream node receives two copies of the multicast traffic; receiving, by the upstream node, a first prune packet from the downstream node through the backup path and stopping sending the multicast traffic to the backup path; receiving, by the upstream node, a second traffic request from the downstream node through the working path after the working path restored; replicating, by the upstream node, the multicast traffic to the restored working path without stopping sending the multicast traffic to the another normal path; receiving, by the upstream node, a second prune packet from the another normal path and stopping sending the multicast traffic to the another normal path; receiving, by the upstream node, a first traffic request from a downstream node through another normal path; replicating, by the upstream node, the multicast traffic to the another normal path without stopping sending the multicast traffic to the backup path so that the downstream node receives two copies of the multicast traffic; receiving, by the upstream node, a first prune packet from the downstream node through the backup path and stopping sending the multicast traffic to the backup path; receiving, by the upstream node, a second traffic request from the downstream node through the working path after the working path restored; replicating, by the upstream node, the multicast traffic to the restored working path without stopping sending the multicast traffic to the another normal path; receiving, by the upstream node, a second prune packet from the another normal path and stopping sending the multicast traffic to the another normal path; wherein the setting up the backup path for the working path that needs to be protected, further comprises: designating a backup egress port as an egress port of a current node; designating a backup ingress port as an ingress port of a downstream node of the current node; and storing the backup egress port and the backup ingress port in the route information, wherein a path between the backup egress port and the backup ingress port is the backup path. designating a backup egress port as an egress port of a current node; designating a backup ingress port as an ingress port of a downstream node of the current node; and storing the backup egress port and the backup ingress port in the route information, wherein a path between the backup egress port and the backup ingress port is the backup path.