The invention discloses a method for establishing hard pipe as well as a method and a device for transmitting messages in a network. The network comprises a plurality of routers and an NMS (network management system). The method comprises the following steps: the NMS acquires the bandwidths of all links in the network; the NMS informs the routers in a network topology of dividing fixed bandwidths in the link bandwidth of the network topology, a sublink is formed by the link for dividing into the fixed bandwidths, and a hard pipeline plane used for bearing a private line service is formed by the sublink and the routers which divide the sublinks; a static MPLS (Multi Protocol Label Switching) label integration is distributed to the hard pipeline plane by the NMS, and the label of the MPLS label in the static MPLS label integration can be transferred by the hard pipeline plane only, therefore, a private line service can be borne in the hard pipeline plane, the bandwidth of the private line service cannot be occupied by other non-private line services, and the private line service which ensures the bandwidth can be provided.