The　unbalance　of　tire　dynamic　balancing　machine　itself　is　an　important　factor　affecting　the　test　accuracy.　The　unbalance　of　the　system　itself　was　usually　subtracted　in　the　subsequent　calculation　without　changing　the　mechanical　structure　in　the　current　study　of　eccentricity　compensation;　therefore,　the　dynamic　balancing　machine　still　worked　in　the　eccentric　state.　According　to　the　problem　of　eccentricity　compensation　for　the　tire　dynamic　balancing　machine,　a　double-plane　eccentricity　compensation　device　with　automatic　adjusting　function　was　proposed.　By　adjusting　four　balance　discs　with　the　electromagnetic　friction　method　to　change　the　synthetic　unbalance　of　the　balance　discs,　the　compensation　was　realized.　The　device　was　installed　in　the　tire　dynamic　balance　testing　machine　and　a　weight　verification　contrast　experiment　was　carried　out.　The　experimental　results　show　that　by　reducing　the　unbalance　of　the　system　itself,　the　better　vibration　signal　is　obtained,　which　reduces　the　interference　of　the　same　frequency,　decreases　the　wear　of　the　system　components,　and　improves　the　testing　precision,　stability　and　repeatability　of　the　system.　©　2018,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.