A　novel　experimental　method　is　proposed　to　investigate　the　fluid　flow　in　rotating　packed　beds　(RPB).　Experimental　results　show　that　the　novel　method　is　simple　and　effective　and　can　be　used　not　only　in　the　lab　experimental　equipment　but　also　in　the　industrial　grade　equipment.　By　using　this　method,　the　hydrodynamic　performances　of　the　RPB　can　be　easily　studied,　which　include　actual　wetting　and　false　wetting,　the　flow　pattern　of　the　liquid　film　flow,　the　number　and　width　of　liquid　trajectories,　etc.,　and　consequently,　their　changing　rules　are　obtained.　The　results　have　significant　effect　on　the　gas-liquid　two　phase　transfer　behavior　and　are　the　basis　of　establishing　accurately　hydrodynamic　mathematical　model　for　RPB.