Low-temperature　bonding　(＜=　300　C-o)　using　Ag　nanoparticles　(Ag　NPs)　is　considered　to　be　the　new　generation　of　bonding　technology　in　power　electronics.　The　oxygen-accelerated　sintering　has　been　observed　by　many　researchers　which　is　attributed　to　the　decomposition　of　organics　covered　on　Ag　NPs.　In　this　work,　organic-free　Ag　NPs　are　fabricated　to　eliminate　the　influence　of　organics,　and　it　is　found　that　the　accelerated　bonding　process　by　oxygen　is　strongly　correlated　to　the　self-confined　amorphous　Ag-O　compound　shell　on　the　surface　of　Ag　NPs.　In　experiments,　the　sintering　process　is　apparently　accelerated　by　the　elevating　oxygen　content,　and　the　amorphous　shell　is　observed　after　sintering,　which　do　not　grow　thicker　even　in　pure　oxygen　ambient　for　a　long　time　while　performing　active　chemical　evolutions.　In　simulations,　the　results　match　well　with　the　experiments　and　indicate　that　the　amorphous　shell　performed　the　dynamic　oxidation　and　decomposition　process.　This　dynamic　equilibrium　is　caused　by　the　instability　of　silver　oxides,　which　would　enable　the　amorphous　shell　to　activate　the　mobility　of　the　surface　mass　flow　and　promote　the　surface　diffusion.　The　shear　strength　of　SiC　chip　increased　by　354%　when　bonding　in　pure　oxygen,　targeting　a　broad　variety　of　applications　in　electronic　packaging.