A method and a network device for realizing shared mesh protection are provided. The method includes the following steps. If a status change of a working label switching path (LSP) is detected, routing information and bandwidth information about the working LSP are notified to every node on a protection LSP corresponding to the working LSP. Every node on the protection LSP calculates a maximal reserved bandwidth of a link based on the received routing information and bandwidth information and adjusts a shared protection bandwidth of the link according to the maximal reserved bandwidth.