With　the　development　of　MEMS　technology　to　the　nanometer　scale,　the　influence　of　different　process　conditions　on　the　performance　of　nano-devices　can　be　calculated　through　the　microscopic　changes　of　materials.　During　the　manufacturing　process,　the　large　residual　stress　from　the　film　stack　significantly　influences　the　performance　of　devices,　thereby　reducing　the　wafer　yield.　Herein,　we　apply　density　functional　theory　to　MEMS　processes　to　reveal　the　intrinsic　mechanism　of　how　residual　stress　affects　the　performance　of　aluminum　nitride-based　bulk　acoustic　wave　(BAW)　resonators　on　an　8-inch　high-resistance　silicon　wafer.　The　variation　rule　of　physical　properties　of　piezoelectric　material　aluminum　nitride　with　different　residual　stresses　is　calculated　via　firstprinciples　calculations.　Through　theory　formula　derivation,　the　piezoelectric-coupling　constant　(K2t　)　of　the　bulk　acoustic　wave　resonator　is　positively　correlated　with　tensile　residual　stress,　and　the　resonant　frequency　(fp,　fs)　is　negatively　correlated　with　tensile　residual　stress.　The　measurement　results　show　that　the　average　shifts　of　K2　eff　is　0.12　%　within　-137　MPa　and　183　Mpa　residual　stress,　which　is　an　excellent　match　with　the　theory　prediction.