The embodiment of the invention provides an LSP pre-deleting method based on MPLS and a device; the method comprises the following steps: receive and resolve a path delete command and obtain LSP information needed to be deleted; inquire service information load-carried on the LSP according to the LSP information needed to be deleted; transmit LSP pre-deleting information to an LSP head node load-carried with the service information according to the service information, so as to lead the LSP head node to carry out service switching according to the LSP pre-deleting information. In the embodiment of the invention, LSP rebuilding and service switching are carried out by resolving the LSP pre-deleting command transmitted by users or software, so as to reduce the working difficulty and intensity of maintenance personnel and realize seamless switching of the bearer service when LSP is maintained and regulated or deleted actively in the complex MPLS network.