The invention discloses a method for realizing multi-protocol data gateway communication, which is suitable for multi-protocol data gateways connected to more than one mobile communication network at the same time. The method includes: a. The corresponding signaling processing module in the data gateway sends an authentication request, and performs authentication through the signaling processing module; b. judge whether the authentication is passed, if passed, continue to establish a data channel, and judge whether the data channel is established successfully , if successful, perform data transmission, enter step c, end if failed; end if not passed; c. judge whether re-registration is required, if necessary, then UE passes the signaling processing corresponding to the mobile communication network to be newly registered The module performs authentication and data channel establishment again, and returns to step b; otherwise, returns to step c. By adopting the method, data communication among various mobile networks, seamless switching, and interconnection between the mobile network and other networks can be realized.