The　low　frequency　response　of　oil　paper　insulation　is　very　important　for　the　diagnosis　of　damp　and　aging　of　insulation.　In　view　of　the　lack　of　analysis　methods　for　low-frequency　response　data　and　the　imperfection　of　the　corresponding　equivalent　circuit　model,　the　Kramers-Kronig　transform　is　used　to　separate　the　conductance,　infinite　frequency　capacitance　and　relaxation　process　in　the　frequency-domain　dielectric　spectrum　of　oil　paper　insulation.　The　Dissado-Hill　model　based　on　multi-body　theory　is　introduced　to　fit　the　low-frequency　relaxation　process.　A　new　oil　paper　insulation　model　is　formulated,　which　is　the　equivalent　circuit　model　of　paper　insulation　for　low　frequency　response.　Finally,　the　low　frequency　response　data　of　oil　paper　insulation　samples　with　different　moisture　content　are　modeled　and　analyzed.　Experimental　results　show　that　the　Kramers-Kronig　transform　can　effectively　decouple　the　relaxation　process,　conductivity　process　and　infinite　frequency　capacitance　of　oil　paper　insulation.　The　goodness　of　fit　of　reconstructed　spectral　lines　of　the　low-frequency　response　model　for　samples　with　different　moisture　content　is　more　than　0.98,　which　evaluateds　the　accuracy　of　the　model.　There　is　an　exponential　function　relationship　between　the　amplitude　of　low-frequency　diffuse　polarizability　χLFD(0)　and　micro　water　content.　The　goodness　of　fit　is　as　high　as　0.99,　which　can　be　utilized　as　a　new　characteristic　quantity　for　quantitative　evaluation　of　moisture　content　of　oil　paper　insulation.　It　provides　a　new　idea　for　diagnosis　of　moisture　affected　state　of　oil　paper　insulation.　©　2021,　Science　Press.　All　right　reserved.