The present invention relates to a wireless communication system and, more specifically, to a method and a device for updating an area of a terminal. A method for processing an area update request of a terminal in a network node, according to one embodiment of the present invention, comprises the steps of: receiving an area update request message from the terminal; and determining whether or not the area update request is accepted on the basis of indication information included in the area update request message when the network is in a congestion state, wherein if the indication information indicates that the terminal has moved to a new area that is not registered, it can be determined that the area update request has been accepted.