An　oil-paper　insulation　state　diagnosis　method　based　on　multiple　parameter　regression　of　recovery　voltage　was　proposed,　which　is　easy　to　be　one-sided　and　inaccurate　in　the　assessment　of　oil-paper　insulation.　Firstly,　according　to　the　field　measured　data　of　different　aging　states　collected　in　recent　10　years,　bringing　in　the　regression　analysis　method,　used　the　furfural　content　in　oil　for　the　y　axis,　with　the　time-domain　characteristic　parameters　for　the　x　axis,　to　establish　a　five　dimensional　regression　system.　Secondly,　the　verification　results　of　this　model　satisfied　the　regression　check,　which　manifest　that　the　calculated　value　of　the　dependent　variable　has　a　certain　correlation　with　the　measured　value,　and　five　parameters　all　have　significant　contribution.　Finally,　according　to　actual　running　state　of　transformers,　the　state　classification　strategy　was　formulated,　and　the　circular　classification　diagram　of　insulation　state　was　constructed,　accuracy　and　credibility　of　the　evaluation　system　were　verified　by　the　measured　data　of　transformers　without　regression　analysis.　This　method　can　provide　new　ideas　for　aging　diagnosis　of　oil-paper　insulation　transformers.　©　2018,　Electrical　Technology　Press　Co.　Ltd.　All　right　reserved.