The present invention discloses a location processing method, an address duplication processing method and apparatus based on an integrated service access gateway/Parlay X gateway. The location processing method includes that: the integrated service access gateway/Parlay X gateway receives location operation requests for multiple terminals by a provided network service interface, wherein the location operation requests are location requests simultaneously initiated for the addresses of multiple terminals; and the integrated service access gateway/Parlay X gateway processes the location operation requests via a service logic processing module, processes the location operation requests according to a predetermined policy in a case that address duplication occurs in the addresses of multiple terminals, and returns policy duplication abnormality and/or location results via the network service interface. The present invention solves the problems of low system developing efficiency and low service processing speed resulting from the processing of user's address duplication in the ISAG/Parlay X gateway, and further achieves the effects of improving the execution efficiency of location service , shortening the response time, and improving the efficiency of developing.