Heart　rate　variability　(HRV),　indicating　the　variation　in　intervals　between　consecutive　heartbeats,　is　a　crucial　physiological　indicator　of　human　health.　This　paper　proposes　a　novel　method　for　multi-person　HRV　monitoring　using　frequency　modulated　continuous　wave　(FMCW)　radar.　Furthermore,　it　incorporates　advanced　techniques　such　as　static　clutter　elimination,　antenna　and　temporal　dimension　stacking,　and　circular　fitting　to　effectively　extract　the　heartbeat　signals　of　multiple　individuals.　Experimental　results　show　that　the　root　mean　square　error　(RMSE)　of　the　detected　inter-beat　interval　(IBI)　is　25.96ms,　which　outperforms　existing　methods.