Abstract: The present invention provides a method and a device for adjusting a trunk state, wherein the method includes: if a media gateway controller receives a request of a new service and thus uses the trunk circuit, sending an adding command message to a media gateway; after receiving the adding command message, the media gateway checking that the trunk circuit is unusable and can not execute the process for the adding command message successfully; the media gateway sending an error response message and a state report message indicating that the trunk circuit is unusable to the media gateway controller; and after receiving the state report message, the media gateway controller modifying the state information of the trunk circuit in the media gateway controller according to the state report message and returning a response message to the media gateway. Therefore, based on the H.