Plasmonic　Ag　core　satellite　nanostructures　were　synthesized　by　utilizing　the　ultrathin　silica　shell　as　a　spacer　to　generate　a　tunable　nanogap　between　the　Ag　core　and　satellites.　To　synthesize　the　nanoparticles,　Ag　nanoparticles　(Ag　NPs)　with　a　diameter　of　similar　to　60　nm　were　synthesized　as　cores,　on　which　Raman　dyes　were　adsorbed　and　then　tunable　ultrathin　silica　shells　from　2.0　to　6.5　nm　were　coated,　followed　by　the　deposition　of　Ag　NPs　as　satellites　onto　the　silica　surface.　The　relationships　between　the　SERS　signal　and　the　important　parameters,　including　the　satellite　diameter　and　the　nanogap　distance,　were　studied　by　experimental　methods　and　theoretical　calculations.　The　maximum　SERS　intensity　of　the　core　satellite　nanoparticles　was　over　14.6　times　stronger　than　that　of　the　isolated　Raman-encoded　Ag/PATP@SiO2　NP.　The　theoretical　calculations　indicated　that　the　local　maximum　calculated　enhancement　factor　(EF)　of　the　hot　spots　with　a　2.0　nm　nanogap　was　9.5　x　10(5).　The　well-defined　Ag　core　satellite　nanostructures　have　a　high　structural　uniformity　and　an　anomalously　strong　electromagnetic　enhancement　for　highly　quantitative　SERS,　leading　to　a　better　understanding　of　hot　spot　formation　and　providing　new　insights　into　the　optimal　design　and　synthesis　of　the　hot　SERS　nanostructures　in　a　controlled　manner.