The invention discloses a method and a system for establishing a label switch path of resource reservation-protocol traffic engineering. The method includes establishing a one-way RSVP-TE (resource reservation-protocol traffic engineering) tunnel; and establishing the P2MPLSP (point to multi-point label switch path) on the basis of the MLDP (multicast label distribution protocol) technology. The P2MPLSP crosses the one-way RSVP-TE tunnel. The method and the system have the advantages that when the MLDP over RSVP-TE tunnel is establish, only the one-way RSVP-TE tunnel needs to be deployed, and the problem of resource waste of an existing method for establishing a tunnel can be solved.