The　serious　dendrite　formation　and　safety　hazards　associated　with　side　reactions　hinder　the　practical　application　of　lithium　metal　batteries.　A　molecular　customization　strategy　based　on　both　physical　and　chemical　properties　is　reported.　A　copolymer　of　acrylamide　and　hexafluorobutyl　acrylate　molecules　is　used　as　an　artificial　solid　electrolyte　interface(ASEI)　for　lithium　metal　to　achieve　dynamic　interface　protection　during　cycling.　The　amide　group　serves　as　the　rigid　unit,　while　the　hexafluorobutyl　group　serves　as　the　flexible　unit,　and　imparts　excellent　mechanical　properties　to　the　copolymer.　Synergistically　abundant　C─F　bonds　exhibit　excellent　water　and　oxygen　resistance　and　have　good　electrolyte　affinity.　The　ester　and　amide　groups　serve　as　amphiphilic　sites　for　Li+　and　PF6−,　regulating　the　ion　flux　at　the　interface　and　achieving　dendrite-free　lithium　deposition.　During　cycling,　the　organic–inorganic　composite　SEI　dynamically　evolves　to　safeguard　the　lithium　metal,　preventing　undue　electrolyte　consumption.　The　copolymer　achieves　stable　cycling　for　1500　and　950 h　at　1　and　2 mA cm−2,　respectively.　It　demonstrates　excellent　performance　with　LiNi0.8Co0.1Mn0.1O2　and　LiFePO4　cathodes.　This　study　introduces　a　new　approach　to　designing　polymers　at　the　molecular　level　to　optimize　the　physical　properties/chemical　activity　of　lithium　metal　interfaces.　©　2024　Wiley-VCH　GmbH.