©　2018　Elsevier　B.V.　Nuclear　power　is　considered　as　the　most　promising　energy　for　power　generation　due　to　low　carbon　emission,　small　fuel　cost,　high　efficiency　and　reliability.　As　a　new　type　of　heat　exchanger,　printed　circuit　heat　exchanger　(PCHE)　with　high　compactness　and　efficiency　can　be　used　for　the　supercritical　carbon　dioxide　(SCO2)　Brayton　power　cycle　in　the　Gen　IV　nuclear　reactor　systems　to　transfer　great　amount　of　heat　from　nuclear　reactors.　The　chemical　etching　technology　plays　an　important　role　in　production　of　heat　transfer　channels　for　PCHEs　from　micron　level　to　millimeter　level.　In　order　to　produce　high-quality　heat　transfer　channels,　the　chemical　spray　etching　method　is　used　in　the　manufacturing　process.　In　this　work,　a　chemical　spray　etching　experiment　was　carried　out　to　analyse　the　etching　phenomenon　on　the　PCHE　channels.　The　influences　of　etching　parameters,　such　as　etching　rate,　lateral　erosion,　surface　roughness,　etc.,　are　investigated.　The　results　showed　that　the　etching　parameters　significantly　affected　the　etching　quality,　which　provided　comprehensive　view　of　details　for　the　etching　process.　Besides,　an　orthogonal　array　testing　strategy　(OATS)　was　adopted　for　chemical　spray　etching　to　synthetically　study　the　influences　of　FeCl3　and　H3PO4　concentrations,　etching　temperature,　spray　pressure　on　the　etching　rate,　the　lateral　erosion　and　the　surface　roughness.　The　optimal　combination　of　etching　parameters　in　the　setting　level　was　investigated　and　obtained,　which　is　in　the　condition　with　spray　gage　pressure　of　0.15　MPa,　etching　temperature　of　35　°C,　FeCl3　concentration　of　400　g·L−1　and　H3PO4　concentration　of　1.5　M.　The　present　work　is　of　significance　to　realize　the　low-cost,　high-efficiency　and　controllable　manufacturing　process　of　PCHEs.