Disclosed by the embodiments of the present invention are a mobile communication terminal and a signal transmission method of the mobile communication terminal. The mobile communication terminal includes a signal output module, a main antenna module, a diversity antenna module, an acquisition module, a control module and a radio-frequency switching module. The acquisition module is used to acquire transmitting power P1 of a transmitted signal when the signal output module generates the transmitted signal and transmits the signal through the main antenna module, and acquire transmission capabilities of the main antenna module and the diversity antenna module when the transmitting power P1 is greater than a first preset value. The control module outputs a corresponding control signal to the radio-frequency switching module according to the transmission capabilities of the main antenna module and the diversity antenna module; and the radio-frequency switching module controls the output module to be connected wit
