A beamforming chip and a radio frequency signal calibration method are provided. The beamforming chip includes a plurality of phase and gain controlling circuits and a calibration circuit. Each phase and gain controlling circuit is configured to change a phase and an amplitude of a received radio frequency input signal to generate a coupling signal. The calibration circuit is coupled to each phase and gain controlling circuit, and configured to select two of the coupling signals, wherein one is a first selected coupling signal before calibration and another one is a second selected coupling signal before calibration. The calibration takes the first selected coupling signal as a reference target to calibrate the phase and the amplitude gain of the second selected coupling signal until there are a minimum phase difference and a closest amplitude between the second selected coupling signal and the reference target.