The present invention provides a message processing method and a label switching router, so as to solve the problem that a current egress label switching router (LSR) can not learn about the LSRs passed by an IP message forwarded in a multi protocol label switching (MPLS) network. The method is applicable to the MPLS network of segment routing (SR) and includes the following steps: an ingress LSR of a label switching path (LSP) tunnel receives an interior gateway protocol (IGP) based notification message transmitted by an egress LSR of the LSP tunnel, wherein the notification message is used to notify the ingress LSR that the egress LSR has the capability of identifying a label history stack; after the notification message is received, an MPLS label stack is inserted into the IP message which enters into the LSP tunnel and an MPLS message is created, wherein, from the top to the bottom of the stack, the MPLS label stack includes: multiple segments, a label history identifier and a label history stack, wherein multiple segments are used to identify the LSRs passed in turn when the MPLS message is forwarded in the LSP tunnel, the label history identifier is used to identify the label history stack included in the MPLS message, and the label history stack includes multiple segments; the MPLS message is transmitted to the egress LSR through the LSP tunnel.