Improving　the　thermal　decomposition　performance　of　hexanitrohexaazaisowurtzitane(CL-20)by　appropriate　methods　is　helpful　to　promote　the　combustion　performance　of　CL-20-based　solid　pro-pellants.In　this　study,we　synthesized　a　sandwich　structure　of　CL-20　and　nanoporous　carbon　scaffolds　film(NCS)and　emphatically　studied　the　thermal　decomposition　performance　of　the　composite　structure.Thermogravimetric　analysis　and　differential　scanning　calorimetry　were　used　to　measure　the　thermal　decomposition　process　of　the　composite　structure.The　kinetic　parameters　of　thermal　decomposition　were　calculated　by　the　thermal　dynamic　analysis　software　AKTS.These　results　showed　that　the　thermal　decomposition　performance　of　the　sandwich　structure　of　CL-20　and　NCS　was　better　than　CL-20.Among　the　tested　samples,NCS　with　a　pore　size　of　15　nm　had　the　best　catalytic　activity　for　the　thermal　decomposition　of　CL-20.Moreover,the　thermal　decomposition　curve　of　the　composite　structure　at　the　heating　rate　of　1　K/min　was　deconvoluted　by　mathematical　method　to　study　the　thermal　decomposition　process.And　a　possible　catalytic　mechanism　was　proposed.The　excellent　thermal　decomposition　per-formance　is　due　to　the　sandwich　structure　enhances　the　interface　reaction　of　CL-20　and　NCS.This　work　may　promote　the　extensive　use　of　CL-20　in　the　field　of　solid　rocket　propellant.