A protection switching method, comprising: receiving, by an intermediate node, a protection switching request message from an upstream neighboring node of the intermediate node, wherein the protection switching request message comprises information about a first protection path; characterized by further comprising: determining, by the intermediate node, according to the information about the first protection path, that a protection path resource of the intermediate node is available; sending, by the intermedia node, a first indication message to the upstream neighboring node of the intermediate node, and sending the protection switching request message to a downstream neighboring node of the intermediate node, wherein the first indication message is used to inform the upstream neighboring node of the intermediate node that the protection path resource of the intermediate node is available; and receiving, by the intermediate node, a second indication message from the downstream neighboring node of the intermediate node, and establishing a cross-connection of the first protection path on the intermediate node, wherein the second indication message is used to inform the intermediate node that a protection path resource of the downstream neighboring node of the intermediate node is available. receiving, by an intermediate node, a protection switching request message from an upstream neighboring node of the intermediate node, wherein the protection switching request message comprises information about a first protection path; characterized by further comprising: determining, by the intermediate node, according to the information about the first protection path, that a protection path resource of the intermediate node is available; sending, by the intermedia node, a first indication message to the upstream neighboring node of the intermediate node, and sending the protection switching request message to a downstream neighboring node of the intermediate node, wherein the first indication message is used to inform the upstream neighboring node of the intermediate node that the protection path resource of the intermediate node is available; and receiving, by the intermediate node, a second indication message from the downstream neighboring node of the intermediate node, and establishing a cross-connection of the first protection path on the intermediate node, wherein the second indication message is used to inform the intermediate node that a protection path resource of the downstream neighboring node of the intermediate node is available. determining, by the intermediate node, according to the information about the first protection path, that a protection path resource of the intermediate node is available; sending, by the intermedia node, a first indication message to the upstream neighboring node of the intermediate node, and sending the protection switching request message to a downstream neighboring node of the intermediate node, wherein the first indication message is used to inform the upstream neighboring node of the intermediate node that the protection path resource of the intermediate node is available; and receiving, by the intermediate node, a second indication message from the downstream neighboring node of the intermediate node, and establishing a cross-connection of the first protection path on the intermediate node, wherein the second indication message is used to inform the intermediate node that a protection path resource of the downstream neighboring node of the intermediate node is available.