The present disclosure relates to a method and a device for controlling congestion in a mobile communication system. A method for controlling congestion of a network node according to the present disclosure comprises the steps of: receiving congestion-related information from at least one base station; transmitting a user equipment information request message for making a request for information on a piece of user equipment corresponding to the base station to a mobility management entity; receiving a user equipment information response message including the information on the user equipment corresponding to the base station from the mobility management entity; and transmitting the information on the piece of user equipment corresponding to the base station to another core network node.