A method for establishing tunnels includes establishing a first unidirectional tunnel from a first node to a second node, and sending a first instruction for establishing a reverse tunnel of the first tunnel, when sending the first instruction to the second node, triggering the establishment of a second unidirectional tunnel from the second node to the first node, and binding the second tunnel to the first tunnel as the reverse tunnel of the first tunnel. A system for establishing tunnels is also provided. The establishment of a reverse tunnel may be automatically triggered after a forward tunnel is established, and a bidirectional tunnel is established.