The present invention relates to a method, a device, and a system for processing a request for closed subscriber group subscription data. A closed subscriber group subscriber server receives a request sent by a mobility management network element. The request includes an identifier of the mobility management network element and an identifier of a user equipment is used for requesting closed subscriber group subscription data of the user equipment. If the closed subscriber group subscription data of the user equipment does not exist, the closed subscriber group subscriber server stores the identifier of the mobility management network element and the identifier of the user equipment.