With　the　large-scale　application　of　the　proton　exchange　membrane　electrolysis　cell　(PEMEC),　the　power　allocation　of　the　multi-stack　PEMEC　system　has　attracted　ever-growing　attention.　However,　fluctuating　power　significantly　affects　the　lifetime　and　energy　efficiency　of　the　system.　In　this　work,　a　power　allocation　strategy　of　the　system　is　proposed　based　on　detailed　modeling　and　characteristics　analysis.　A　complete　model　of　PEMEC　is　developed　considering　bubble　coverage　for　research　of　operating　characteristics.　To　analyze　the　energy　efficiency　characteristics　of　the　system,　a　power　model　of　the　PEMEC　stack　is　established.　A　mathematical　method　to　real-time　obtain　the　frontier　of　optimal　energy　efficiency　of　stacks　is　also　proposed.　The　degradation　model　of　the　proton　exchange　membrane　is　developed　to　determine　the　safe　operation　boundary.　And　then　considering　the　operating　status,　voltage　degradation　is　introduced　to　characterize　the　degradation　of　PEMEC　dynamically.　Finally,　a　power　allocation　strategy　is　proposed　considering　the　system＇s　energy　efficiency　and　degradation.　Furthermore,　a　composite　revenue　function　is　presented　to　compare　the　performance　of　different　power　allocation　strategies.　The　results　show　that　the　system　has　the　highest　consolidated　revenue　under　the　proposed　strategy.　Current　work　is　conducive　to　the　popularization　and　generalization　of　the　multi-stack　PEMEC　system.　©　2023　Hydrogen　Energy　Publications　LLC