The invention discloses a base-station radio-frequency testing system applicable to an LTE (Long Term Evolution) system and a testing method. The base-station radio-frequency testing system is connected with a base station to be tested and is used for testing radio-frequency data of the base station to be tested. The base-station radio-frequency testing system comprises a frequency-spectrum analyzer, a channel simulator, a useful signal generator, an interference signal generator, a broadband signal generator, a power meter, a main control computer and a radio-frequency box, wherein the main control computer is connected with the frequency-spectrum analyzer, the channel simulator, the useful signal generator, the interference signal generator, the broadband signal generator, the power meter and the radio-frequency box; the radio-frequency box is connected with the frequency-spectrum analyzer, the channel simulator, the useful signal generator, the interference signal generator, the broadband signal generator, the power meter and the base station to be tested; the power meter is connected with the broadband signal generator; the radio-frequency box comprises a switch, a load, an isolator, a coupler, an attenuator, a combiner, a multi-frequency combiner and a radio-frequency interface.