A switch route exploring method, system and device are provided in the present invention. The method comprises that: a transmitting source node NSource constructs a switch route exploring request packet and transmits it to a destination node NDestination; the switch route exploring request packet comprises information of switch route from the transmitting source node NSource to the destination node NDestination, wherein the information is known by the transmitting source node NSource; and the destination node NDestination constructs a switch route exploring response packet and transmits it to the transmitting source node NSource.