The　generation　of　cyclic　carbonates　by　the　cycloaddition　of　CO2　with　epoxides　is　attractive　in　the　industry,　by　which　CO2　is　efficiently　used　as　C1　source.　Herein,　a　series　of　catalysts　were　developed　to　efficient　mediate　the　cycloaddition　of　CO2　with　epoxides　to　generate　carbonates.　The　catalysts　were　easily　synthesized　via　the　amine-formaldehyde　condensation　of　ethidium　bromide　with　a　variety　of　linkers.　The　newly　prepared　heterogeneous　catalysts　have　high　thermal　stability　and　degradation　temperatures.　The　surface　of　the　catalysts　is　smooth　and　spherical　in　shape.　The　effect　of　temperature,　pressure,　reaction　time　and　catalyst　dosage　on　the　cycloaddition　of　CO2　with　epoxide　were　investigated.　The　results　show　that　the　catalyst　with　1,3,5-tris(4-formylphenyl)benzene　as　the　linker　can　achieve　97.4　%　conversion　efficiency　at　the　conditions　of　100　°C,　reaction　time　of　12　h,　and　the　reaction　pressure　of　1.2　MPa　in　a　solvent-free　environment.　Notably,　the　polymers　serve　as　homogeneous　catalysts　during　the　reaction　(reaction　temperature　above　Tg)　and　can　be　separated　and　recovered　easily　as　homogeneous　catalysts　at　room　temperature.　In　addition,　the　catalyst　is　not　only　suitable　for　a　wide　range　of　epoxide　substrates,　but　also　can　be　recycled　many　times.　Furthermore,　DFT　calculations　show　that　the　coordination　between　the　electrophilic　center　of　the　catalyst　and　the　epoxide　reduces　the　energy　barrier,　and　the　reaction　mechanism　is　proposed　based　on　the　reaction　kinetic　studies　and　DFT　calculations.　©　2022　Wiley-VCH　GmbH.