Fabricating　nanocrystalline　bright　copper　coatings　is　crucial　for　protection　and　decoration.　A　novel　brightener　organic　anion　acid　blue　1　(AB1)　was　used　to　obtain　nanocrystalline　bright　copper　coatings.　The　suppressing　effect　of　AB1　was　verified　and　analyzed　by　electrochemical　tests.　Further　insights　into　the　effect　mechanism　of　AB1　were　investigated　through　density　functional　theory　(DFT)　calculations,　molecular　dynamics　(MD)　simulations　and　in　situ　Raman　spectra.　The　phenomena　of　adsorption　of　AB1　on　copper　surface　discovered　by　MD　simulation　and　in　situ　Raman　spectra,　coupled　with　coordination　interaction　between　-　SO3-　of　AB1　and　free　Cu2+,　synergistically　inhibit　the　growth　of　copper　coatings,　resulting　that　compact　and　flat　copper　plating　coatings　were　formed.　The　electroplating　condition　and　copper　coating　morphology　were　studied,　respectively.　Bright　flat　copper　coatings　can　be　obtained　with　100　to　200　mg/L　AB1　under　5　A/dm2.　Besides,　mass　spectrum　(MS)　was　used　to　evaluate　the　stability　of　AB1.　The　phase　structure　under　the　influence　of　AB1　concentration　was　studied　using　XRD.　With　the　increase　of　AB1　concentration,　the　(111)　surface　is　preferentially　obtained.　The　average　grain　size　of　optimized　copper　coating,　calculated　according　to　Scherrer＇s　formula,　is　about　11　nm,　indicating　the　acquisition　of　nanocrystalline　copper　plating　coating.　Finally,　copper　coatings　obtained　are　of　good　corrosion　resistance　owing　to　low　roughness　and　small　grain　size.