In　order　to　explain　the　microscopic　mechanism　of　oil-paper　insulation　material＇s　dielectric　response　in　a　sufficiently　wide　frequency　range　in　depth　and　comprehensively,　the　present　study　considers　both　the　universal　relaxation　law　and　classical　theoretical　model　in　dielectric　physics.　By　taking　full　advantage　of　the　thermal　characteristics　of　dielectric　processes,　barrier　height,　as　an　intrinsic　parameter,　the　method　was　proved　to　be　effective　in　establishing　connection　between　frequency　domain　spectroscopy　test　and　thermally　stimulated　current　when　observing　same　dielectric　process　in　the　two　aspects.　Further,　with　the　correlation　between　the　real　and　imaginary　parts　of　complex　permittivity　curve　as　well　as　the　first　order　partial　differential　equation　of　response　spectrum　data,　a　synthetical　analysis　that　effectively　reveals　microscopic　mechanisms　of　dielectric　process　in　frequency　domain　is　established.　With　this　newly　developed　method,　the　results　illustrate　that　in　a　relatively　large　temperature　range,　oil-paper＇s　response　curve　is　generated　by　independent　dielectric　processes　which　are,　respectively,　low　frequency　dispersion,　conductance,　electrode　polarization,　interfacial　polarization　and　dipole　polarization.　These　processes＇　generation　mechanisms,　function　expressions　and　occurrence　conditions　are　also　clarified　according　to　quantitative　study.　By　revealing　the　charge　carriers＇　motion　law　in　relatively　wide　frequency　band,　the　present　study　contributes　to　the　theory　explanation　and　application　of　frequency　domain　spectrum.　©　2021　Chin.　Soc.　for　Elec.　Eng.