Passivation　treatment　is　the　last　key　process　to　ensure　the　service　life　of　copper　foil　for　lithium-ion　batteries.　Although　chromic　anhydride　commonly　used　in　industry　has　an　efficient　passivation　effect,　it　can　threat　human　health　and　the　environment.　Herein,　an　environmentally　friendly　passivator　is　prepared　from　pomelo　peel　by　a　simple　and　economical　solution　extraction　method,　which　makes　copper　foil　have　good　anti-corrosion　properties　in　air,　chlorine-containing　solution,　and　organic　electrolyte.　Electrochemical　methods　and　X-ray　photoelectron　spectroscopy　(XPS)　confirm　the　potential　of　pomelo　peel　extractant　(PP)　to　replace　chromic　anhydride　as　a　passivating　agent　for　copper　foil.　The　interaction　mechanism　between　PP　and　copper　foil　is　analyzed　by　adsorption　models,　and　the　efficient　passivation　behavior　of　PP　for　copper　foil　is　consistent　with　the　Langmuir　model.　Density　Functional　Theory　(DFT)　calculations　of　the　naringin　(main　component　of　PP)　is　performed　to　further　reveal　the　protection　mechanism　of　PP　on　copper　foil.　In　addition,　the　copper　foil　treated　by　PP　still　has　excellent　electrochemical　performance　as　lithium-ion　battery　current　collector,　indicating　that　the　presence　of　PP　not　only　protects　the　copper　foil　from　corrosion,　but　also　does　not　affect　the　conductivity　of　the　copper　foil.　This　research　provides　a　new　insight　into　the　chrome-free　passivation　of　copper　foils,　which　is　in　line　with　the　development　concept　of　green　production.