A method for fast protection switching in multicast, the method being performed by a routing node in a multicast routing network and comprising: determining a primary path and a secondary path to a source node, wherein the secondary path and the primary path have a minimum tail coincidence, wherein the minimum tail coincidence means that nodes at a tail end of the primary path coincide with nodes at a tail end of the secondary path, and a quantity of the coinciding nodes is minimum; receiving, by using both the primary path and the secondary path, multicast traffic replicated by an upstream neighboring node, and replicating multicast traffic received by the primary path to a downstream neighboring node; and if the primary path is faulty, replicating multicast traffic received by the secondary path to the downstream neighboring node, characterized in that the determining a primary path and a secondary path to a source node, wherein the secondary path and the primary path have minimum tail coincidence comprises: determining a shortest path to the source node as the primary path; determining whether at least one path to the source node exists exclusive of the primary path; and if at least one path to the source node exists exclusive of the primary path, using a shortest path of the at least one path to the source node as the secondary path; or if the path to the source node does not exist exclusive of the primary path, using a last hop Nx of the primary path as a last hop of the secondary path, and performing the step of determining the secondary path to the source node, and further comprising: if the last hop Nx of the primary path is used as the last hop of the secondary path and the secondary path to the source node does not exist, using last two hops of the primary path as last two hops of the secondary path, and performing the step of determining the secondary path; and if the last two hops of the primary path are used as the last two hops of the secondary path and the secondary path to the source node does not exist, deducing the rest by analogy until the secondary path to the source node is determined. determining a primary path and a secondary path to a source node, wherein the secondary path and the primary path have a minimum tail coincidence, wherein the minimum tail coincidence means that nodes at a tail end of the primary path coincide with nodes at a tail end of the secondary path, and a quantity of the coinciding nodes is minimum; receiving, by using both the primary path and the secondary path, multicast traffic replicated by an upstream neighboring node, and replicating multicast traffic received by the primary path to a downstream neighboring node; and if the primary path is faulty, replicating multicast traffic received by the secondary path to the downstream neighboring node, characterized in that the determining a primary path and a secondary path to a source node, wherein the secondary path and the primary path have minimum tail coincidence comprises: determining a shortest path to the source node as the primary path; determining whether at least one path to the source node exists exclusive of the primary path; and if at least one path to the source node exists exclusive of the primary path, using a shortest path of the at least one path to the source node as the secondary path; or determining a shortest path to the source node as the primary path; determining whether at least one path to the source node exists exclusive of the primary path; and if at least one path to the source node exists exclusive of the primary path, using a shortest path of the at least one path to the source node as the secondary path; or if the path to the source node does not exist exclusive of the primary path, using a last hop Nx of the primary path as a last hop of the secondary path, and performing the step of determining the secondary path to the source node, and further comprising: if the last hop Nx of the primary path is used as the last hop of the secondary path and the secondary path to the source node does not exist, using last two hops of the primary path as last two hops of the secondary path, and performing the step of determining the secondary path; and if the last two hops of the primary path are used as the last two hops of the secondary path and the secondary path to the source node does not exist, deducing the rest by analogy until the secondary path to the source node is determined. if the last hop Nx of the primary path is used as the last hop of the secondary path and the secondary path to the source node does not exist, using last two hops of the primary path as last two hops of the secondary path, and performing the step of determining the secondary path; and if the last two hops of the primary path are used as the last two hops of the secondary path and the secondary path to the source node does not exist, deducing the rest by analogy until the secondary path to the source node is determined.