This　paper　mainly　studies　the　influence　of　nano/micro　Al2O3　and　Al(OH)(3)　in　epoxy　composites　on　the　ablation　resistance,　by　quantifying　the　mass　loss　and　observing　the　surface　topography　of　sample　after　several　times　surface　flashover　in　vacuum　(the　peak　value　is　approximately　10kA,　and　the　wave　front　is　8us,　wave　tail　is　20us(8/20us)).　The　experimental　results　show　that　the　addition　of　inorganic　filler　to　epoxy　resin　is　useful　for　improving　the　ablation　resistance.　The　performance　of　Al(OH)(3)　filler　is　much　better　than　Al2O3.　Nano-particles　are　much　smaller　and　dispersed　more　uniformly　than　micro-particles.　Thus　the　composite　with　nano　aluminium　hydroxide　is　of　better　heat　dissipation.　But　the　blocking　effect　of　adding　micro-particles　is　better　than　adding　nano-particles.