A method for realizing multi-party conference service in a telecommunication network with NGN network Architecture, characterized in that a basic call media gateway, MGW, does not support a multi-party conference bridge, and the method comprises an operation for establishing multi-party conference services when a call between a user A and a user B is maintained, and a call between the user A and a user C is in an active state, comprising the following steps of: the user A sending a multi-party conference establishment request message to a MSC server to request establishing a multi-party conference between the user A, B and C; MSC server sending a Modify command to the media gateway to request it stopping sending call maintaining tone to the remote user B; MSC server sending a Move command to the media gateway to request the media gateway turning a terminal T A from a context C AC to a new context, that is, newly established context CA; MSC server sending an ADD command to a media gateway supporting the multi-party conference bridge, to request a multi-party media gateway, MGW MPTY, establishing a new context and a new terminal, that is, context C MPTY and terminal T A0; MSC server sending the ADD command to the media gateway supporting the multi-party conference bridge to request a MGW MPTY establishing a new terminal in a context C MPTY, that is, terminal T B0; MSC server sends the ADD command to the media gateway supporting the multi-party conference bridge to request the MGW MPTY establishing a new terminal in the C MPTY, that is, terminal T C0; MSC server sending the ADD command to the media gateway to request the media gateway establishing a new terminal in a context C A, that is, terminal T A1; MSC server sending the ADD command to the media gateway to request the media gateway establishing a new terminal in a context C AB, that is, terminal T B1; MSC server sending the ADD command to the media gateway to request the media gateway establishing a new terminal in a context C AC, that is, terminal T C1; and after accomplishing the terminal operation, notifying the remote user B that the maintained call has been restored and added to the multi-party conference; notifying the remote user C that the call has been added to the multi-party conference; notifying the user A that the multi-party conference has been established successfully. the user A sending a multi-party conference establishment request message to a MSC server to request establishing a multi-party conference between the user A, B and C; MSC server sending a Modify command to the media gateway to request it stopping sending call maintaining tone to the remote user B; MSC server sending a Move command to the media gateway to request the media gateway turning a terminal T A from a context C AC to a new context, that is, newly established context CA; MSC server sending an ADD command to a media gateway supporting the multi-party conference bridge, to request a multi-party media gateway, MGW MPTY, establishing a new context and a new terminal, that is, context C MPTY and terminal T A0; MSC server sending the ADD command to the media gateway supporting the multi-party conference bridge to request a MGW MPTY establishing a new terminal in a context C MPTY, that is, terminal T B0; MSC server sends the ADD command to the media gateway supporting the multi-party conference bridge to request the MGW MPTY establishing a new terminal in the C MPTY, that is, terminal T C0; MSC server sending the ADD command to the media gateway to request the media gateway establishing a new terminal in a context C A, that is, terminal T A1; MSC server sending the ADD command to the media gateway to request the media gateway establishing a new terminal in a context C AB, that is, terminal T B1; MSC server sending the ADD command to the media gateway to request the media gateway establishing a new terminal in a context C AC, that is, terminal T C1; and after accomplishing the terminal operation, notifying the remote user B that the maintained call has been restored and added to the multi-party conference; notifying the remote user C that the call has been added to the multi-party conference; notifying the user A that the multi-party conference has been established successfully.