Herein,　the　coupling　relationship　between　molecule　structure　and　ion　conductivity　in　silica　filled　silicone　gel　are　established.　Based　on　the　broadband　dielectric　spectrum,　the　concentration　of　ion　charges　and　ions　diffusion　coefficients,　two　key　roles　for　ion　conductivity,　are　calculated.　The　concentration　of　ion　charges　is　increased　by　about　four　orders　of　magnitude　after　the　addition　of　silica.　Because　of　the　more　short-length　chains　conformations　and　more　amorphous　regions　at　interfaces,　the　chains　at　interfaces　are　easier　to　rearrange　with　higher　relaxation　frequency,　which　enhances　the　ions　diffusion　process　and　contributes　to　negative　decoupling　exponents　between　the　interface　molecule　relaxations　and　ion　diffusion　coefficients　in　silicone　gel　composites.　With　the　increase　of　fumed　silica　loading,　the　ionic　conductivity　increases　first　and　decreases　owing　to　percolation　phenomenon　about　silica　dispersion.　Meanwhile,　decoupling　exponents　of　the　interface　molecules　are　closer　to　0.　Our　findings　deepen　the　understanding　how　the　interface　structures　act　on　ions　conductivity　in　insulating　polymer　composites,　which　is　critical　to　rationally　design　interface　structures　for　manipulating　the　insulation　performances.　©　2024　Elsevier　Ltd