The present application relates to the communications field, and discloses a network device addressing method, device, and system to achieve network device addressing. A specific implementation method includes: constructing, by an interworking function IWF, a host name of a mobility management network element according to an integrated services digital network ISDN number of the mobility management network element; sending, by the IWF, a request message to a home subscriber server HSS, where the request message includes the host name of the mobility management network element; and after receiving a response message sent by the HSS, acquiring, by the IWF, an ISDN number of the HSS according to a host name of the HSS, and sending the ISDN number of the HSS to the mobility management network element.