Method for releasing source network resource, gateway entity and network appliance

The invention discloses a method for releasing source network resources, a gateway entity and a network device. The method comprises the following steps: judging whether the switching from a source network to an objective network is already completed; transmitting resource releasing messages to the source network by the gateway entity of the objective network when the judgment of the switching is completed; receiving response messages released and completed by the resources returned from the source network. The method can serve the function of releasing the source carrying resources, thereby achieving the technical effect of enhancing the service efficiency of the source network resources.