Air-source　autocascade　steam　generating　heat　pumps　have　the　capability　to　produce　high-temperature　steam　from　low-temperature　air,　thereby　playing　a　critical　role　in　the　global　energy　transition　by　aiding　the　industrial　decarbonization.　Among　the　key　elements　influencing　the　performance　of　autocascade　steam　generating　heat　pumps　is　the　mixed　refrigerant　gas-liquid　phase　separation　efficiency.　This　research　proposes　an　optimization　strategy　for　two-phase　refrigerant　separation　through　using　the　advanced　exergy　method　to　address　this　challenge.　An　improved　autocascade　steam　generating　heat　pump　model　is　developed　based　on　this　strategy.　The　study　conducts　an　extensive　comparison　between　the　conventional　and　improved　systems　of　autocascade　steam　generating　heat　pump　over　prolonged　operational　periods,　assessing　their　performance　across　energy,　exergy,　economic,　and　environmental　dimensions.　The　results　indicate　that　the　improved　system　significantly　outperforms　the　conventional　system.　Specifically,　when　the　waste　heat　temperature　of　30　degrees　C,　the　improved　system　demonstrates　an　average　increase　of　20.36　%　in　the　coefficient　of　performance　and　a　51.37　%　rise　in　steam　mass　flow　rate　under　year-round　ambient　conditions.　Furthermore,　the　improved　system　achieves　an　average　CO2　reduction　rate　of　84.37　%　and　a　comparable　enhancement　in　operational　economic　efficiency.　However,　the　performance　gains　of　the　improved　system　diminish　as　the　availability　of　waste　heat　temperature　increases,　with　performance　degradation　observed　when　waste　heat　temperature　reaches　a　critical　threshold.　These　results　underscore　the　potential　of　the　proposed　optimization　strategy　to　guide　the　design　of　autocascade　cycles　and　the　development　of　steam　generating　heat　pumps,　offering　valuable　theoretical　insights　for　advancing　sustainable　industrial　heating　technologies.