With　the　climate　conditions　in　northwest　Qinghai　and　the　characteristics　of　local　rural　adobe　buildings,　the　harmonic　Fourier　series　to　express　the　outdoor　sol-air　temperature　function　is　adopted　as　outside　boundary　conditions　for　wall　thermal　analysis.　Based　on　the　theory　of　wall　thermal　system,　time　lag　and　decrement　factor　of　the　adobe　wall　before　and　after　the　thermal　insulation　renovation　are　calculated　with　Matlab.　The　net　heat　loss　of　the　wall　and　the　inner　surface　fluctuation　temperature　are　calculated　by　the　harmonic　reaction　method.　The　results　show　that　the　heat　loss　of　the　wall　is　reduced　to　a　greatly　extent　after　the　insulation　renovation,　and　the　energy　saving　rate　of　the　wall　reaches　up　to　74%　and　the　inner　surface　temperature　has　an　increase　from　3.4-4.7,　which　not　only　improves　the　indoor　radiation　field　temperature,　but　also　makes　the　indoor　radiation　field　be　more　uniform,　thus　increasing　the　thermal　comfort　of　the　interior　personnel.　At　the　same　time,　the　research　and　analysis　for　our　new　residential　design　provides　a　quantitative　basis　and　scientific　understanding.　©　2019,　Editorial　Board　of　Acta　Energiae　Solaris　Sinica.　All　right　reserved.