In　this　study,　an　innovative　cooling　channel　filled　with　a　novel　X-type　truss　array　structure　was　proposed　to　improve　the　cooling　effect　of　turbine　blade　mid-chord　region.　The　flow　and　heat　transfer　characteristics　of　the　X-type　truss　array　cooling　channel　were　analyzed　numerically.　The　influences　of　Reynolds　number　(ReH　=　10,000-60,000),　truss　rod　diameter　ratio　(d/H　=　0.1-0.3),　transverse　spacing　ratio　(Xs/C　=　1-3)　and　streamwise　spacing　ratio　(Zs/C　=　1-3)　on　the　cooling　performance　of　X-type　truss　array　channel　were　investigated.　Then　the　empirical　correlations　of　heat　transfer　coefficient　and　friction　factor　were　obtained　by　nonlinear　regression　method　for　the　X-type　truss　array　cooling　channel.　The　results　show　that　horseshoe　vortexes　form　around　each　truss　rod　of　truss　elements.　The　high　heat　transfer　regions　mainly　appear　in　the　downstream　of　each　truss　rod　on　the　channel　wall　as　well　as　the　windward　side　of　truss　rod　surface.　Increasing　ReH　can　effectively　enhance　the　heat　transfer　coefficient　of　the　X-type　truss　array　cooling　channel,　but　has　little　influence　on　the　friction　factor　of　the　channel.　When　d/H　increases　from　0.1　to　0.3,　the　friction　factors　of　the　X-type　truss　array　channel　increases　about　3.5-4.4　times,　and　the　average　Nusselt　numbers　of　the　channel　increase　by　57.5%-87.9%.　When　Xs/C　increases　from　1　to　3,　the　friction　factors　and　the　average　Nusselt　numbers　of　the　channel　decrease　by　83.9%-85.1%　and　44.9%-57.7%　respectively.　The　friction　factor　and　average　Nusselt　number　of　X-type　truss　array　cooling　channel　both　first　increase　and　then　decrease　with　the　increase　of　Zs/C.　The　moderate　values　of　d/H,　Xs/C　and　Zs/C　can　make　the　comprehensive　thermal　performance　of　X-type　truss　array　cooling　channel　better.　The　results　may　provide　a　guidance　and　reference　for　the　application　of　X-type　truss　array　structure　in　the　internal　cooling　channel　of　advanced　gas　turbine　blades.　©　2021　The　Author(s).　Published　by　Elsevier　Ltd.