According to a method, when it is detected that service traffic needs to be switched from a first optical layer path to a second optical layer path, a first internet protocol (IP) link associated with the service traffic needs to be determined, and an IP link used to transmit the service traffic is adjusted from the first IP link to a second IP link; an optical layer path of the first IP link is switched from the first optical layer path to the second optical layer path after the adjustment of the IP link is completed; and the IP link used to transmit the service traffic is adjusted from the second IP link to the first IP link after the switching of the optical layer path is completed. In this way, continuity of the service traffic can be ensured.