The invention discloses a reconfigurable multi-frequency-range transceiver radio-frequency front end which comprises a receiver part, a transmitter part and a frequency synthesizer, wherein the receiver part comprises a low-noise amplifier, a first-stage reconfigurable lower frequency converter, a second-stage orthogonal lower frequency converter and a first medium-frequency circuit which are sequentially connected; the first medium-frequency circuit is connected with a digital baseband modem; the transmitter part comprises a second medium-frequency circuit, a first-stage low-frequency upper frequency converter, a second-stage high-frequency upper frequency converter and a power amplifier; the second medium-frequency circuit is connected with the digital baseband modem; the frequency synthesizer comprises a phase lock ring; a frequency output of the phase lock ring is connected with the first-stage reconfigurable lower frequency converter, an orthogonal oscillator and a multi-phase filter; the orthogonal oscillator is connected with the second-stage orthogonal lower frequency converter and the first-stage low-frequency upper frequency converter; and an output of the multi-phase filter is connected with the second-stage high-frequency upper frequency converter. According to a reconfiguration method, a zero medium-frequency structure and a sliding medium-frequency structure are synthesized, so that the performance of a transceiver is improved, and the power consumption of the transceiver is reduced.