Abstract: A service protection method includes a first node that determines that a fault has occurred on a first working path, and generates a service switching message based on the fault on the first working path. The first node sends the service switching message on a first protection path, where the service switching message indicates to adjust a bandwidth of a service from a guard bandwidth to a target bandwidth, where the guard bandwidth represents a pre-occupied bandwidth of the first protection path before the service is transmitted, where the target bandwidth represents an occupied bandwidth for transmitting the service on the first protection path, and where the guard bandwidth is less than the target bandwidth.