Mode　switching　between　fuel　cell　and　electrolytic　mode　is　inevitable　for　actual　applications.　During　the　mode　switching,　complicated　electrical　response　and　gas-liquid　phase　change　occur　due　to　the　different　operation　conditions　in　these　two　modes.　To　explore　the　effect　of　water　removal　method　on　electrical　performance　before　fuel　cell　mode　startup　in　mode　switching　process　and　get　better　overall　cell　performance.　In　this　paper,　the　continuous　mode　switching　within　three　cycles　is　explored　by　experimental　works.　It　is　found　that　the　voltage　decreases　slightly　with　the　cycle　running,　and　the　two-phase　flow　in　the　corresponding　mode　of　each　cycle　is　similar　through　analyzing　the　two-phase　flow　phenomenon　of　the　two　modes　during　mode　switching.　It　is　also　found　that　bubbles　are　generated　during　electrolytic　cell,　the　water　is　consumed　and　there　is　only　water　mist　at　the　transparent　end　plate　during　electrolytic　cell　mode　without　water.　A　handful　of　liquid　water　gathers　at　the　bottom　of　the　flow　channel　during　fuel　cell　mode.　Experiments　of　the　cycle　test　process　are　also　conducted.　It　is　shown　that　with　the　cell　mode　switching　periodically,　the　cell　voltages　of　the　electrolytic　cell　and　fuel　cell　both　decrease　periodically.　The　fuel　cell　performance　changes　more,　especially　under　high　current　density.