A method for establishing an inter-layer link binding relationship, comprising: receiving, by a first node, a first label switched path, LSP, path establishment request message, wherein the first LSP path establishment request message carries first link information, and the first link information comprises a link identifier of a single-wavelength link comprised in a first LSP and a link identifier of a multiplexing link comprised in the first LSP; and establishing, by the first node, an inter-layer link binding relationship of the first LSP, wherein the inter-layer link binding relationship of the first LSP is a correspondence between the link identifier of the multiplexing link in the first LSP and the link identifier of the single-wavelength link in the first LSP; the method further comprising: receiving, by the first node, a second LSP path establishment request message, wherein the second LSP path establishment request message carries second link information, and the second link information comprises a link identifier of a single-wavelength link comprised in a second LSP and a channel identifier of an electrical-layer channel comprised in the second LSP; and establishing, by the first node, an inter-layer link binding relationship of the second LSP, wherein the inter-layer link binding relationship of the second LSP is a correspondence between the link identifier of the single-wavelength link in the second LSP and the channel identifier of the electrical-layer channel in the second LSP. receiving, by a first node, a first label switched path, LSP, path establishment request message, wherein the first LSP path establishment request message carries first link information, and the first link information comprises a link identifier of a single-wavelength link comprised in a first LSP and a link identifier of a multiplexing link comprised in the first LSP; and establishing, by the first node, an inter-layer link binding relationship of the first LSP, wherein the inter-layer link binding relationship of the first LSP is a correspondence between the link identifier of the multiplexing link in the first LSP and the link identifier of the single-wavelength link in the first LSP; the method further comprising: receiving, by the first node, a second LSP path establishment request message, wherein the second LSP path establishment request message carries second link information, and the second link information comprises a link identifier of a single-wavelength link comprised in a second LSP and a channel identifier of an electrical-layer channel comprised in the second LSP; and establishing, by the first node, an inter-layer link binding relationship of the second LSP, wherein the inter-layer link binding relationship of the second LSP is a correspondence between the link identifier of the single-wavelength link in the second LSP and the channel identifier of the electrical-layer channel in the second LSP. receiving, by the first node, a second LSP path establishment request message, wherein the second LSP path establishment request message carries second link information, and the second link information comprises a link identifier of a single-wavelength link comprised in a second LSP and a channel identifier of an electrical-layer channel comprised in the second LSP; and establishing, by the first node, an inter-layer link binding relationship of the second LSP, wherein the inter-layer link binding relationship of the second LSP is a correspondence between the link identifier of the single-wavelength link in the second LSP and the channel identifier of the electrical-layer channel in the second LSP.