Based　on　a　two-dimensional,　two-phase,　non-isothermal　model　of　unitized　regenerative　fuel　cell　coupled　with　electrochemical　reaction,　four　kinds　of　stepped　flow　channels　were　designed　and　compared　with　straight　flow　channel　and　shallow　straight　flow　channel　with　the　same　inlet　depth.　The　cell　electrical　performance,　temperature　distribution　and　power　consumption　were　studied　under　fuel　cell　mode　and　electrolytic　cell　mode.　The　results　show　that　gradually　shallow　stepped　flow　channel　has　better　electrical　performance,　drainability　and　temperature　uniformity　in　fuel　cell　mode.　Under　electrolytic　cell　mode,　the　performance　of　gradually　deep　stepped　channel　is　better　than　that　of　gradually　shallow　stepped　channel.　A　mode　switching　method　of　changing　the　inlet　and　outlet　of　oxygen　channel　is　proposed,　which　can　improve　the　comprehensive　performance　of　unitized　regenerative　fuel　cells.　©　2021,　Science　Press.　All　right　reserved.