Theoptimizationdesignofthepowersystemisessentialforstratosphericairshipswithparadoxicalrequirementsofhighreliabilityandlowweight.Themethodologyoforthogonalexperimentispresentedtodealwiththeproblemoftheoptimizationdesignoftheairship’spowersystem.Mathematicalmodelsofthesolararray,regenerativefuelcell,andpowermanagementsubsystem(PMS)arepresented.Thebasictheoryofthemethodoforthogonalexperimentisdiscussed,andtheselectionoffactorsandlevelsoftheexperimentandthechoiceoftheevaluationfunctionarealsorevealed.TheproposedmethodologyisvalidatedintheoptimizationdesignofthepowersystemoftheZhiYuan-2stratosphericairship.Resultsshowthattheoptimalconfigurationiseasilyobtainedthroughthismethodology.Furthermore,theoptimalconfigurationandthreesub-optimalconfigurationsareintheParetofrontierofthedesignspace.Sensitivityanalysesfortheweightandreliabilityoftheairship’spowersystemarepresented.