An LTE cellular mobile network access system and a corresponding communication method are provided. The system includes a SIM card interface device, a mobile terminal, and a NRS accessing to a domestic cellular mobile network. The SIM card interface device is configured to hold a SIM card and forward authentication information of the SIM card to the NRS via the mobile terminal. The mobile terminal is in communication with the NRS via the Internet and is configured to register on the NRS and transmit signaling data and voice data to the NRS. The NRS is configured to establish a standard S1 connection with the domestic cellular mobile network and transmit the signaling data and the voice data to the domestic cellular mobile network.