Abstract: The present disclosure discloses a local oscillator feedthrough signal correction apparatus, including a microprocessor control unit, a first digital-to-analog converter, a second digital-to-analog converter, a mixer, a local oscillator, a signal output line, a signal splitter, and a detector tube. The signal splitter is disposed in the signal output line, and the first digital-to-analog converter and the second digital-to-analog converter are configured to provide the mixer with quadrature direct current components VI and VQ used for local oscillator feedthrough signal correction. The mixer outputs a local oscillator feedthrough signal to the signal output line. The signal splitter obtains the local oscillator feedthrough signal by means of splitting, and the detector tube detects the local oscillator feedthrough signal.