Molten　salt　and　supercritical　CO2　(sCO(2))　have　been　selected　as　the　two　most　promising　heat　transfer　fluids　in　the　3rd　generation　of　solar　thermal　power　generation,　so　it　is　very　important　to　study　their　heat　transfer　and　flow　characteristics　for　the　design　of　heat　exchanger.　This　research　studies　thermohydraulic　performance　of　molten　salt　and　sCO(2)　in　a　printed　circuit　heat　exchanger　(PCHE)　with　different　channel　configurations.　A　PCHE　unit　with　straight　channel　for　molten　salt　and　discontinuous　fin　for　sCO(2)　was　selected　for　the　fin　shape　optimization　of　sCO(2)　side.　Results　show　that　the　newly　proposed　Fin　II　channel　can　reduce　the　flow　resistance　of　sCO(2)　compared　with　the　airfoil　Fin　I,　and　Fanning　friction　factor　can　be　decreased　by　11.93%　at　the　expense　of　Colburn　factor　decreased　by　2.24%.　The　mechanism　of　heat　transfer　enhancement　is　analyzed　by　using　field　synergy　principle,　and　the　results　show　that　the　temperature　field,　velocity　field　and　pressure　field　have　better　synergy　in　the　Fin　II　channel.　The　optimal　finned　channel　improves　the　comprehensive　performance　of　PCHE,　which　contributes　to　the　third　generation　of　solar　thermal　power　generation.