Display server and method for migrating state of subscribe status machine

The embodiment of the invention discloses a method for transferring the state of a subscription state machine of a presentation server, which is to solve the problem that the state machine of the presentation server of the prior art has poor processing capacity. The method disclosed by the embodiment of the invention comprises the following steps: the presentation server receives a subscription request of an observation body to the presentation information of a presentation body; the subscription state machine of the observation body to the presentation body is established; a notification message is sent to the observation body; when the response of the observation body to the notification message is abnormal, the presentation server produces an abnormal error event, the subscription state machine of the presentation server carries out state transferring according to the abnormal error event. When the response is abnormal, the subscription state machine carries out the state transferring according to the abno