Given　the　serious　net　power　decline　and　excessive　mass　of　the　system　in　heavy　power　fuel　cells　(FCs)　operating　at　variable　altitudes,　optimizing　and　matching　the　appropriate　air　compressor　of　FC　emerged　as　a　prominent　area　of　research.　This　study　aims　to　perform　multi-objective　and　multi-parameter　optimization　of　the　FC　air　loop　to　improve　the　performance　of　the　FC　system　for　heavy　power　under　a　variable　altitude　environment.　Based　on　the　experimental　test　data,　combined　with　semi-empirical　and　semi-mechanism　equations,　five　air　compressor　models　with　different　power　levels　were　developed,　and　their　performance　covered　the　altitude　from　0　to　4000　m.　Pareto　theory　is　introduced　to　evaluate　the　three-dimensional　objectives　of　cathode　system　mass,　isentropic　efficiency,　and　system　net　power　under　different　air　supply　parameters　and　different　power　levels　of　air　compressors.　The　Pareto　front　is　solved　by　a　multi-objective　particle　swarm　optimization　(MOPSO)　algorithm　under　different　altitudes.　The　results　show　that　compared　with　the　single-objective　PSO　with　customized　weight　summation　(PSO1　and　PSO2),　MOPSO　improves　2.38%　and　8.89%　for　net　power,　respectively.　The　three　objectives　for　the　optimized　configuration　are　−12.20%　(0.61%),　15.87%　(27.40%),　and　23.96%　(−2.74%)　improved　than　baseline1　(baseline2)　for　the　4000　m　altitude.　©　2024