The　composite　nanostructure　emitter　of　multiwalled　carbon　nanotubes　and　graphenes　was　deposited　on　pyramidal　silicon　substrate　by　the　simple　larger　scale　electrophoretic　deposition　process.　The　field　emission　(FE)　properties　of　the　composite/pyramidal　Si　device　were　greatly　improved　compared　with　that　of　the　composite/plain　Si.　The　low　turn-ON　electric　field,　the　low　threshold　electric　field,　and　the　larger　enhancement　factor　were　obtained　using　the　pyramidal　structure.　The　better　FE　performances　of　the　composite/pyramidal　Si　were　a　combined　effect　of　the　field　enhancement　from　the　composite　emitter　and　the　pyramidal　Si　structure.　The　numerical　simulation　of　the　electric　field　distribution　on　composite/pyramidal　cathode　was　used　to　illuminate　the　improved　FE　properties　by　using　the　pyramidal　substrate.　These　studies　indicate　that　constructing　composite/pyramidal　structure　is　one　of　the　efficient　ways　to　improve　the　FE　properties.　©　2014　IEEE.