Proton　exchange　membrane　fuel　cell(PEMFC)　has　the　advantages　of　high　specific　energy,　clean　and　efficient.　As　one　of　the　core　structures　of　PEMFC,　the　structure　size　of　channel　has　an　important　impact　on　the　gas　transmission　and　liquid　water　removal.　Selecting　appropriate　size　parameters　is　of　great　significance　for　practical　operation.　Taking　50　mm　×50　mm　single　serpentine　channel　cell　as　the　research　object,　a　three￣dimensional　two￣phase　isothermal　model　of　PEMFC　was　established　by　numerical　simulation.　The　effects　of　channel　depth,　channel　width　and　channel　ridge　width　on　cell　current　density,　gas　mass　transfer　characteristics,　net　output　power　and　drainage　performance　were　analyzed.　Results　show　that　with　the　decrease　of　channel　depth　and　channel　width,　the　oxygen　concentration　involved　in　the　reaction　increases,　the　current　density　increases,　the　net　output　power　increases,　the　drainage　performance　of　the　catalytic　layer　improves,　and　the　cell　performance　improves　gradually.　With　the　decrease　of　the　ridge　width　of　the　channel,　the　oxygen　concentration　participating　in　the　reaction　gradually　increases,　and　the　current　density　increases,　however,　the　increase　of　the　net　output　power　in　the　channel　is　comparatively　small,　and　the　increase　of　the　oxygen　concentration　is　comparatively　slow.　©　2023　Beijing　University　of　Technology.　All　rights　reserved.