Embodiments of the present invention provide a method, a device, and a system for creating a bidirectional multicast distribution tree based on an interior gateway protocol, the method includes: generating, according to a root address of a first node flooded by the first node through an IGP and a shortest path tree algorithm, a shortest path to another node with the first node as a source node, and constructing a flooding tree according to the shortest path; and when receiving layer 3 multicast group information flooded by an edge node, determining, according to the layer 3 multicast group information and a multicast group range that is supported by the first node, a flooding tree corresponding to each layer 3 multicast group, and performing pruning, according to the layer 3 multicast group information, to the flooding tree corresponding to each layer 3 multicast group, to generate a bidirectional multicast distribution tree.