A protection switching method, comprising: interrupting, by a first end node, transmission of a service flow and sending a protection switching request message to a downstream neighboring node of the first end node when a working trail between the first end node and a second end node is faulty, wherein the protection switching request message comprises information about a first protection trail, the first protection trail comprises the first end node, the second end node, and at least one intermediate node, the at least one intermediate node is located between the first end node and the second end node, and the downstream neighboring node of the first end node is a node among the at least one intermediate node; determining, by each intermediate node among the at least one intermediate node according to the information about the first protection trail, whether a protection path resource of the intermediate node is available; if the protection path resource of the intermediate node is unavailable, returning, by the intermediate node, a protection switching failure message; and if the protection path resource of the intermediate node is available, establishing, by the intermediate node, a cross-connection of the intermediate node occupied by the first protection trail, and sending the protection switching request message to a downstream neighboring node of the intermediate node, wherein the downstream neighboring node of the intermediate node is an intermediate node or the second end node; and establishing, by the second end node according to the protection switching request message, a cross-connection of the second end node occupied by the first protection trail, and returning a confirmation message to the first end node, so that the first end node continues the transmission of the service flow over the first protection trail according to the confirmation message. interrupting, by a first end node, transmission of a service flow and sending a protection switching request message to a downstream neighboring node of the first end node when a working trail between the first end node and a second end node is faulty, wherein the protection switching request message comprises information about a first protection trail, the first protection trail comprises the first end node, the second end node, and at least one intermediate node, the at least one intermediate node is located between the first end node and the second end node, and the downstream neighboring node of the first end node is a node among the at least one intermediate node; determining, by each intermediate node among the at least one intermediate node according to the information about the first protection trail, whether a protection path resource of the intermediate node is available; if the protection path resource of the intermediate node is unavailable, returning, by the intermediate node, a protection switching failure message; and if the protection path resource of the intermediate node is available, establishing, by the intermediate node, a cross-connection of the intermediate node occupied by the first protection trail, and sending the protection switching request message to a downstream neighboring node of the intermediate node, wherein the downstream neighboring node of the intermediate node is an intermediate node or the second end node; and establishing, by the second end node according to the protection switching request message, a cross-connection of the second end node occupied by the first protection trail, and returning a confirmation message to the first end node, so that the first end node continues the transmission of the service flow over the first protection trail according to the confirmation message.