Herein,　the　robust　core-satellite　Ag/TiO2/Ag　composite　nanospheres　were　successfully　developed.　We　firstly　fabricated　large　silver　nanoparticles　with　sufficient　plasmonic　activity　as　cores　and　then　encapsulated　uniform　titanium　dioxide　interlayer　shell　around　Ag　cores,　which　serves　as　the　highly　functionalized　substrates　to　achieve　uniform　and　plentiful　surface　chemical　properties.　Next,　the　outer　shell　of　small　silver　satellites　was　formed　in-situ　via　controllable　reduction　of　AgNO3　by　n-butylamine,　which　acts　as　the　remarkable　enhancer　for　surface　enhanced　Raman　scattering　(SERS).　The　Ag/TiO2/Ag　composite　nanospheres　with　exceptional　SERS　sensitivity　were　easily　prepared　via　facilely　tuning　the　coverage　and　grain　sizes　of　silver　satellites.　Then　the　optimized　Ag/TiO2/Ag　composite　nanospheres　were　employed　to　quantitatively　detect　methylene　blue　(MB)　in　solution.　The　results　showed　good　linear　relationship　between　SERS　intensities　and　logarithm　concentrations　of　MB　and　the　limit　of　detection　is　low　to　10−10　M.　Moreover,　the　highly　uniform　and　robust　Ag/TiO2/Ag　composite　nanospheres　display　outstanding　reproducibility　(RSD　=　4.02%)　and　highly　storage　stability.　Owing　to　the　intrinsic　catalytic　activity　of　small　Ag　satellites,　Ag/TiO2/Ag　nanospheres　were　further　applied　to　effectively　follow　the　degradation　reaction　process　of　crystal　violet　by　SERS.　Altogether,　the　core-satellite　Ag/TiO2/Ag　nanospheres　present　multiple　SERS　application　potential　in　various　fields,　such　as　quantitative　chemical　analysis,　trace　detection　of　pollutants　and　in-situ　reaction　monitoring.　©　2019　Elsevier　B.V.