Power　cables　in　the　urban　power　supply　system　are　laid　in　cable　trenches　or　directly　buried　underground,　and　the　insulation　is　susceptible　to　corrosion　and　penetration,　causing　local　insulation　aging　or　abrasion.　Early　detection　of　soft　faults　helps　prevent　power　system　faults　from　occurring.　This　paper　proposes　a　method　that　can　detect　cable　multi-point　soft　faults　and　distinguish　fault　types　based　on　Frequency　Domain　Reflectometry　(FDR).　Firstly,　we　establish　a　numerical　calculation　model　of　distributed　parameters　to　analyze　the　impedance　spectroscopy　characteristics　of　different　types　of　defects　and　the　positioning　methods　and　errors.　Next,　a　simulation　study　was　carried　out　for　different　characteristics　of　aging　and　damage,　which　means　different　types　of　soft　faults　were　successfully　distinguished.　Then,　based　on　the　results　of　the　simulation,　experiments　are　carried　out　to　verify　the　effectiveness　of　the　positioning　algorithm　and　the　feasibility　of　distinguishing　defect　types.　Simulation　and　experiment　show　that　the　positioning　error　is　within　0.5%　and　1%　simultaneously.　Compared　with　traditional　location　methods,　the　defect　location　method　proposed　in　this　paper　can　determine　the　type　and　severity　of　the　defect　while　locating　multiple　defects.　The　experimental　results　show　that　the　defect　identification　method　proposed　in　this　paper　has　great　potential　for　field　application.　©　2021　IEEE.