Disclosed by the embodiments of the present document are a mobile communication terminal including a signal output module, a main antenna module, a diversity antenna module, an acquisition module, a control module and a radio-frequency switching module, and a signal transmission method. The acquisition module is used to acquire transmitting power P1 of a transmitted signal when the signal output module generates the transmitted signal to transmit through the main antenna module, and acquire transmission capabilities of the main antenna module and the diversity antenna module when 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 with the main antenna module or the diversity antenna module according to the control signal.
