Vital sign detection method and device based on millimeter wave radar

The invention discloses a vital sign detection method and device based on millimeter wave radar, and belongs to the technical field of radar signal processing, and the method comprises the steps: carrying out the fast Fourier transform of radar echo intermediate frequency signal data, and obtaining a frequency spectrum and a phase spectrum of an intermediate frequency signal; suppressing interference in the frequency spectrum by using a phasor mean cancellation algorithm; performing incoherent accumulation on the multi-frame data; searching a maximum value in a human body target distance range, and obtaining a distance unit corresponding to the target; extracting a phase at a distance unit corresponding to the target from the phase spectrum and expanding the phase, and calculating a body surface displacement curve of the target; separating breathing and heartbeat signals; and respectively performing spectrum estimation on the breathing and heartbeat signals obtained by separation, and obtaining corresponding