Drawn　on　the　experience　of　the　heat-flow-meter　method,　an　experimental　system　is　designed,　established　and　validated　to　investigate　the　thermal　insulation　performance　of　SiC　opacifier　doped　silica　aerogel　at　large　temperature　difference.　The　test　section　of　the　experimental　system　is　a　symmetrical　sandwich-structure,　while　the　temperature　of　the　cold　surface　keeps　constant　by　circulating　the　water　from　the　thermostat,　NESLAB　ThermoFlex2500,　and　the　hot　surface　is　electrically　heated.　Compared　with　the　traditional　method　of　the　back-surface　temperature　response,　the　cold　surface　temperature　is　quantitatively　controllable.　Based　on　the　present　experimental　system　and　method,　the　thermal　insulation　performance　of　insulator　can　be　qualitatively　and　quantitatively　evaluated　by　analyzing　the　temperature　responses　of　the　hot　surface　through　the　whole　heat　transfer　process　including　the　initial　steady-state,　the　unsteady-state,　and　the　final　new　steady-state.　Qualitatively,　the　higher　the　temperature　of　the　hot　surface　is　and　the　faster　the　temperature　rise　of　the　hot　surface　is,　the　better　the　thermal　insulation　performance　of　the　material　has;　quantitatively,　the　effective　thermal　conductivity　of　the　materials　is　obtained　based　on　the　semi-infinite　medium　model　and　Fourier＇s　Law.　The　present　results　show　that　the　effective　thermal　conductivities　of　silica　aerogel　doped　by　3.5　μm　SiC　opacifier　with　different　volume　fraction　of　0%,　1%,　and　5.84%　are　about　0.02559　W　m−1　K−1,　0.02844　W　m−1　K−1,　and　0.03305　W　m−1　K−1,　respectively,　at　small　temperature　difference　(400　K),　the　thermal　insulation　performance　of　silica　aerogel　doped　by　3.5　μm　SiC　particle　with　a　volume　fraction　of　1%　is　good　enough,　though　3.5　μm　SiC　particle　with　a　volume　fraction　of　5.84%　has　a　marginal　improvement　in　blocking　the　thermal　radiation　within　silica　aerogel.　©　2020　Elsevier　Masson　SAS