A path establishment method and a controller are disclosed. The method includes: when detecting a path establishment request for establishing P2MP TE, computing a P2MP TE path by using head node information and tail node information included in the path establishment request; identifying a target branch node in the P2MP TE path, and obtaining a label of the target branch node; and when a third node corresponding to the head node information and the target branch node are not a same node, sending first information to the third node, and sending second information to the target branch node, where the second information is used to instruct the target branch node to generate a multicast forwarding entry. Embodiments of this application can reduce complexity of establishing the P2MP TE path.