To　enhance　water　management　in　proton　exchange　membrane　fuel　cells,　the　influence　of　drying　and　flooding　on　performance　in　different　voltage　ranges　is　investigated　by　experiment.　The　current　density　attenuates　as　the　voltage　decreases　in　the　concentration　polarization　range.　Through　the　analysis　of　the　performance　curves　under　different　conditions,　the　performance　attenuation　is　due　to　the　high　current　and　overpotential　at　low　voltage,　which　leads　to　the　temperature　rising　and　drying　up.　At　high　flow　rates,　the　current　attenuates　at　low　voltages,　indicating　that　the　current　density　attenuation　is　not　because　of　flooding　and　insufficient　reactants.　According　to　calculations,　the　anode　water　content　is　low　due　to　more　protons　and　water　being　transferred　from　anode　toward　cathode　at　the　high　current,　which　causes　the　current　density　to　attenuate.　From　the　current　ratio,　the　cell　can　generate　an　additional　current　density　of　3.2%　at　0.1　V　voltage,　which　can　evaluate　the　degree　of　carbon　corrosion　and　water　electrolyzation　due　to　the　insufficient　supply　of　reactants.　In　addition,　the　voltage　undershoot　of　switching　to　high　current　is　great,　and　the　fuel　cell　has　a　high　demand　for　water.　Finally,　reducing　temperature　and　increasing　humidification　can　alleviate　the　attenuation　of　current　density.