Molecular　dielectric　switches　constitute　a　type　of　intelligent　materials　that　are　highly　coveted　for　their　distinctive　advantages　of　switchable　dielectric　responses,　lightweight,　and　mechanical　flexibility.　Twodimensional　(2D)　hybrid　perovskites　have　demonstrated　excellent　promise　for　assembling　dielectric　switches,　in　which　the　dynamic　motions　of　organic　moieties　afford　driving　force　to　trigger　switchable　dielectric　phase　transition.　Here,　we　successfully　assembled　a　new　lead-free　hybrid　double　perovskite,　(CHA)4　CuBiBr8　(　1　,　CHA　=　cyclohexylammonium),　adopting　a　typical　2D　structural　motif,　which　shows　dielectric　anisotropy　and　bistable　behaviors　during　the　reversible　phase　transition　near　Tc　=　378　K　(the　Curie　temperature).　That　is,　its　dielectric　constants　could　be　switched　and　tuned　between　high-dielectric　and　low-dielectric　states.　Structure　analyses　reveal　that　the　ordered-disordered　transformation　of　the　organic　CHA+　moiety　and　distortion　of　inorganic　framework　account　for　its　phase　transition.　This　result　will　stimulate　further　exploration　of　molecular　dielectric　switches　in　this　2D　environmentally　friendly　family.　(c)　2024　Published　by　Elsevier　B.V.　on　behalf　of　Chinese　Chemical　Society　and　Institute　of　Materia　Medica,　Chinese　Academy　of　Medical　Sciences.