A method for routing a call between a calling party and a called party by a media gateway, comprising setting a master control network element in a media gateway cluster, and characterized in that, establishing a mapping relationship between a user number and a media gateway in the master control network element, the method further comprising: acquiring, by the media gateway, a user number of the called party and requesting the master control network element to determine a called media gateway to which the called party belongs according to a number matching result, when the media gateway determines that an uplink protocol interface between the media gateway and a core network equipment is interrupted; determining, by the master control network element, the called media gateway to which the called party belongs according to the established mapping relationship, and informing the media gateway initiating the request; and completing the call between the media gateway as a calling media gateway that initiates the request and the determined called media gateway to which the called party belongs; wherein the step of establishing a mapping relationship between a user number and a media gateway comprises: after each media gateway in the media gateway cluster is initiated, reporting user number information within a local media gateway to the master control network element; storing, by the master control network element, the received user number information of all the media gateways in the media gateway cluster locally; and establishing, by the master control network element, a mapping relationship between each user number and the media gateway to which it belongs; or pre-configuring the mapping relationship on the master control network element manually. acquiring, by the media gateway, a user number of the called party and requesting the master control network element to determine a called media gateway to which the called party belongs according to a number matching result, when the media gateway determines that an uplink protocol interface between the media gateway and a core network equipment is interrupted; determining, by the master control network element, the called media gateway to which the called party belongs according to the established mapping relationship, and informing the media gateway initiating the request; and completing the call between the media gateway as a calling media gateway that initiates the request and the determined called media gateway to which the called party belongs; wherein the step of establishing a mapping relationship between a user number and a media gateway comprises: after each media gateway in the media gateway cluster is initiated, reporting user number information within a local media gateway to the master control network element; storing, by the master control network element, the received user number information of all the media gateways in the media gateway cluster locally; and establishing, by the master control network element, a mapping relationship between each user number and the media gateway to which it belongs; or pre-configuring the mapping relationship on the master control network element manually.