Abstract: VIP has excellent thermal insulation performance,the thermal resistance of which is ten times higher thanconventional insulation materials.Through analysis on effective thermal conductivity of VIP,it is indicated that the maininfluence items on VIP thermal performance are solid thermal conduct and radiation heat transfer,while the influence ofgas thermal conduct and convection heat transfer is negligible.The main parameters that influence the whole thermalperformance of VIP is temperature,gas pressure,water content,core density,core granule and so on.