We　introduce　a　multi-parameter　combined　objective　function　of　heat　engines　under　the　strong　coupling　and　symmetry　condition　and　derive　the　universal　expression　of　the　optimization　efficiency.　The　results　obtained　show　that　the　optimization　efficiency　derived　from　the　multi-parameter　combined　objective　function　include　a　variety　of　optimization　efficiencies,　such　as　the　efficiency　at　the　maximum　power,　efficiency　at　the　maximum　efficiency-power　state,　efficiency　at　the　maximum　ecological　or　unified　trade-off　function,　and　Carnot　efficiency.　It　is　further　explained　that　these　results　are　also　suitable　for　the　endoreversible　cycle　model　of　the　Carnot　heat　engines　operating　between　two　heat　reservoirs.　©　2017　Walter　de　Gruyter　GmbH,　Berlin/Boston　2017.