We　propose　a　frequency-sweeping　interferometry　(FSI)　with　single　external　cavity　diode　laser　that　can　be　used　to　measure　the　absolute　distances　of　a　dynamic　target.　Generally,　the　FSI-Doppler　effect　induced　by　target　drift　restricts　the　measurement　accuracy　severely,　but　the　Doppler　effect　can　also　be　used　to　measure　the　actual　movement　during　optical　frequency　sweeps.　Thus,　a　mathematical　model　of　the　Doppler　effect　in　FSI　is　presented　and　a　novel　FSI　method　based　on　Doppler　beat　frequency　tracking　model　is　proposed　to　realize　the　absolute　distance　measurement　of　a　dynamic　target.　The　method　was　verified　successfully　by　measuring　vibrating　targets　of　50　similar　to　5000　Hz　at　38　mm　in　the　laboratory.