To　obtain　compatible　properties　of　low　thermal　conductivity　and　high　thermal　stability,　Al0.6CoCrFeNiTi　high-entropy　alloy　was　designed　as　a　novel　candidate　of　metal-based　thermal　barrier　coatings　(MBTBCs).　The　corresponding　high-entropy　alloy　coatings　were　fabricated　by　both　high-velocity　oxygen-fuel　spraying　(HVOF)　and　atmospheric　plasma　spraying　(APS),　and　then　the　dependence　of　thermal　insulation　properties　on　microstructure　was　investigated.　The　both　coatings　exhibit　a　simple　body-centered　cubic　(BCC)　structure,　but　present　obvious　difference　in　microstructure　and　defect　characters　which　relates　to　the　evolution　of　in-flight　particles.　Benefit　from　the　extremely　low　thermal　conductivity,　the　APS-deposited　coating　can　increase　13.24　°C　of　the　surface　temperature　of　piston　crown　and　yield　a　temperature　reduction　of　19.00　°C　along　the　thickness　direction,　which　mean　a　positivity　on　enhancing　the　power　efficiency　of　vehicle　engines　without　sacrificing　the　strength　of　aluminum　alloy　components.　In　virtue　of　a　decoupling　method,　the　crucial　effect　of　microstructure　on　thermal　conductivity　is　disclosed,　thus　interpreting　the　excellent　thermal　insulation　property　of　APS-deposited　coating　dominated　by　grain　refinement　and　disordered　BCC　structure.　The　present　results　demonstrate　a　great　potential　of　high-entropy　alloy　coatings　as　thermal　barrier　application　and　provide　an　inspiration　for　future　works　aiming　to　design　these　coatings　to　meet　specific　engineering　needs.　©　2023