The　environmental　friendly　polishing　liquid　was　used　to　polish　the　surface　of　Hastelloy　C-276　alloy　substrate,　which　was　used　for　the　technical　route　of　ion　beam　assisted　deposition　(IBAD).The　typical　curve　of　anodic　polarization　was　obtained,　and　the　mechanism　of　electrochemical　polishing　was　described.　The　effect　of　electrochemical　polishing　elements　(such　as　electrolytic　polishing　temperature,　polishing　time　and　polishing　distance)　on　the　roughness　of　substrate＇s　surface　was　investigated.　The　high　quality　surface　with　the　roughness　lower　than　5　nm　(in　the　area　of　5　μm×5　μm)　was　obtained　via　the　optimized　polishing　processes,　which　satisfied　to　the　requirements　of　surface　roughness　for　the　subsequent　deposition　by　IBAD.　Citric　acid　in　polishing　liquid　decomposed　into　a　complexing　agent　at　about　50,　which　could　accelerate　the　precipitation　of　metal　ions　and　increase　the　reactivity　of　surface.　©　2017,　Materials　Review　Magazine.　All　right　reserved.