Under　thermophysical　conditions　of　real　vane　material,　the　conjugate　heat　transfer　method　is　applied　for　numerical　investigation　on　the　flow　and　heat　transfer　characteristics　of　cooling　jet　flow　in　the　impingement　chamber　at　the　vane　leading　edge.　In　this　paper,　we　have　analyzed　the　influence　of　offset　distance　(2.5　mm,　5.0　mm,　7.5　mm　and　10.0　mm)　of　the　impingement　hole　and　the　mass-flow　ratio　(1.0%,　1.5%,　2.0%,　2.5%　and　3.0%)　of　the　impingement　cooling　air　to　the　mainstream　on　the　composite　cooling　performance　of　the　vane　leading　edge,　the　convection　heat　transfer　performance　of　impingement　target　surface　and　film　cooling　performance　of　suction　surface.　The　result　shows　that　the　offset　structure　of　the　impingement　hole　has　a　significant　influence　on　the　cooling　performance　of　vane　leading　edge.　When　the　offset　distance　is　small,　the　composite　cooling　performance　of　the　leading　edge　and　convection　heat　transfer　performance　of　target　surface　will　be　weakened;　when　the　offset　distance　is　large,　the　composite　cooling　performance　of　the　leading　edge　and　convection　heat　transfer　performance　of　target　surface　will　be　strengthened.　Especially,　it　has　a　significant　improvement　effect　on　convection　heat　transfer　performance　of　target　surface.　Among　the　four　impingement　hole　offset　structures,　the　average　Nusselt　number　of　the　structure　with　the　largest　offset　distance　is　increased　by　up　to　33.97%　approximately　compared　with　the　target　surface　without　offset　structure.　The　film　cooling　performance　of　the　suction　surface　is　generally　negative　correlation　with　the　circumferential　distance　from　the　impingement　hole　to　the　film　cooling　hole　of　suction　surface:　the　farther　the　impingement　hole　is　from　the　film　cooling　hole,　the　weaker　the　film　cooling　performance　of　the　suction　surface.　Compared　with　the　non-offset　structure,　the　average　film　cooling　effectiveness　of　the　suction　surface　is　increased　by　about　5.56%　and　decreased　by　about　10.96%　respectively　when　the　impingement　hole　is　close　to　or　deviates　from　the　film　cooling　hole.　When　the　mass-flow　ratio　of　the　impingement　coolant　is　relatively　small,　increasing　the　mass-flow　ratio　of　the　coolant　could　effectively　improve　the　cooling　performance　of　the　vane　leading　edge.　The　average　overall　cooling　efficiency　of　leading　edge,　the　average　Nusselt　number　on　the　target　surface　and　the　average　film　cooling　effectiveness　on　the　suction　surface　could　be　improved　by　up　to　26.78%,　103.94%　and　56.67%　respectively.　However,　when　the　mass-flow　ratio　of　coolant　is　too　large,　the　coolant　at　the　outlet　of　the　film　cooling　hole　will　fall　off　the　wall　surface　and　mixing　with　the　mainstream,　seriously　affecting　the　film　coolant　coverage　of　leading　edge　and　suction　surface.　©　2022,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.