The　cycloaddition　between　CO2　and　epoxides　to　produce　cyclic　carbonate　is　an　attractive　and　efficiency　pathway　for　the　utilization　of　CO2　as　C1　source.　The　development　of　catalyst　to　mediate　cycloaddition　between　CO2　and　epoxides　at　low　temperature　and　pressure　is　still　a　challenge.　Herein,　a　series　of　polypyrazoles　with　glass　transition　temperature　(Tg)　in　the　range　of　42.3–52.5　°C　were　synthesized　and　served　as　catalyst　to　mediate　the　cycloaddition　of　CO2　and　epoxides　by　the　assistant　of　tetrabutylammonium　bromide.　The　catalytic　behaviors　of　polypyrazole　on　the　model　cycloaddition　of　CO2　to　epichlorohydrin,　including　the　reaction　parameters　optimization　and　versatility　were　investigated　in　detail,　and　excellent　yield　(99.9%)　and　selectivity　(99%)　were　obtained　under　the　optimized　reaction　conditions　of　70　°C　and　1.0　MPa　for　6.0　h.　Noteworthily,　the　polypyrazole　acts　as　homogeneous　catalyst　during　reaction　(higher　than　Tg).　And　under　room　temperature,　polypyrazoles　can　be　easily　separated　and　recovered,　which　is　a　promising　feature　of　a　heterogeneous　catalyst.　Furthermore,　the　reaction　mechanism　was　proposed.　The　DFT　calculation　suggested　that　the　formation　of　hydrogen　bond　between　pyrazole　and　epoxide　greatly　reduced　the　energy　barrier,　which　play　an　important　role　in　promoting　CO2　cycloaddition.　©　2022　The　Chemical　Industry　and　Engineering　Society　of　China,　and　Chemical　Industry　Press　Co.,　Ltd.