The　performance　of　the　printed　circuit　heat　exchanger　(PCHE),　an　important　component　in　the　supercritical　carbon　dioxide　(S-CO2)　Brayton　cycle,　affects　the　efficiency　of　the　system.　This　study　aims　to　improve　the　performance　of　airfoil　PCHE　by　investigating　the　effect　of　the　airfoil-fin　structure　on　its　flow　and　heat　transfer　performance.　Herein,　for　the　high-temperature　return　heaters　in　the　S-CO2Brayton　cycle　system,　a　numerical　simulation　method　is　used,　with　S-CO2　selected　as　the　heat　transfer　medium.　By　comparing　the　flow　and　heat　transfer　performance　of　the　airfoil-fin　channels　of　NACA0020　with　three　different　structures,　we　study　the　influence　of　the　positional　parameter　of　the　maximum　thickness　of　the　airfoil　fins　on　the　chord　length　on　the　performance　of　the　heat　exchanger　and　analyze　the　rule　of　change　in　terms　of　the　thermo-hydraulic　performance,　comprehensive　indexes,　overall　fluidity,　local　performance,　etc.　Results　show　that　the　heat　transfer　performance　increases　as　the　maximum　thickness　of　the　airfoil　fins　approaches　the　leading　edge　of　the　airfoil　along　the　chord　length　while　maintaining　a　constant　relative　thickness　in　the　airfoil-fin　structure.　Compared　to　the　other　two　airfoil-fin　channels,　the　airfoil-fin　channel　of　NACA0020-20　exhibits　a　larger　j　factor　and　Nu　of　2.7%—8.8%　and　2.7%—8%,　respectively,　under　the　selected　operating　conditions.　This　airfoil-fin　structure　can　effectively　reduce　the　influence　of　the　boundary　layer　and　improve　the　heat　transfer　performance　in　the　PCHE.　Overall,　its　performance　is　even　better　than　the　other　two　airfoil　fins.　These　results　provide　a　certain　basis　for　the　structural　design　and　performance　optimization　of　the　airfoil　PCHE.　©　2024　Editorial　office　of　Energy　Storage　Science　and　Technology.　All　rights　reserved.