A mobile terminal is provided including: a fixed network access control module for connecting the terminal with an analog user line and notifying the central processor that the mobile terminal is connected with the fixed telephone network in the situation where the analog user line is connected to the analog user line interface; a dual-tone multi-frequency processing module for identifying a selecting signal from analog user line and sending it to central processor; a call processing module for extracting a voice signal on the analog user line, sending it to an audio output device, and sending a voice signal from user to the analog user line; a mobile communication module for achieving communication between the mobile terminal and the exterior; and the central processor for processing the signaling from dual-tone multi-frequency processing module and sending the signaling to be transmitted via network to the dual-tone multi-frequency processing module.