Provided are a method and device for synchronizing an interface parameter. According to the method, related information, sent by a remote Terminating Provider Edge (TPE) of a first Pseudo-Wire (PW) in a first segment of PW of a Switching Provider Edge (SPE), of the first PW is received or recorded, wherein the related information of the first PW carries an interface parameter of the remote TPE of the first PW, and the interface parameter is used for establishing a Label Switch Path (LSP); and the related information of the first PW is sent to a remote TPE of a second segment of PW of the SPE. By the solution, a problem caused by incapability of opposite equipment in timely perceiving updating of an interface parameter of local equipment is solved, and the opposite equipment can use a correct interface parameter value for negotiation and PW establishment.