Aiming　at　the　problem　of　inaccurate　aging　assessment　of　single　characteristic　quantity　in　the　oil-paper　insulation　dielectric　response　method，the　grade　cloud　model　is　proposed　to　assess　the　aging　state　of　oil-paper　insulation　with　multiple　characteristic　quantities.　First，the　matrix　pencil　method　is　used　to　identify　the　parameters　of　the　equivalent　circuit，and　two　new　time-domain　characteristic　quantities　that　can　characterize　the　aging　state　of　the　geometric　branch　and　the　polarization　branch　are　proposed　respectively.　Then，the　comprehensive　weight　calculation　is　performed　in　combination　with　the　subjective　and　objective　weighting　methods.　Finally，the　grade　cloud　model　is　used　to　construct　the　assessment　model　of　the　aging　state　of　the　equipment.　According　to　the　theory　and　the　actually　measured　data　of　the　cloud　model，the　digital　characteristics　of　each　standard　grade　cloud　model　are　obtained.　The　correlation　calculation　of　the　various　indexes　of　the　equipment　to　be　assessed　and　the　standard　grade　cloud　model　is　performed　to　obtain　the　insulation　aging　grade　of　the　equipment.　It　is　proved　by　a　number　of　examples　that　the　assessment　results　obtained　by　this　method　can　correctly　reflect　the　real　condition　of　the　equipment　and　have　high　application　feasibility.　©　2023　Xi＇an　High　Voltage　Apparatus　Research　Institute.　All　rights　reserved.