The present invention relates to the field of network communication technologies, and discloses a method, a device, and a system for establishing an on-demand route. The method includes: determining that a stable route needs to be established; establishing the stable route and recording a route entry corresponding to the stable route in a route table; determining an effective time of the stable route, in which the effective time of the stable route is longer than the effective time of another common route; and performing an aging operation on the route entry according to the effective time of the stable route. With the present invention, requirements of different applications on the delay may be satisfied, and the consumption of the network bandwidth may be reduced.