With　the　rapid　development　of　offshore　wind　power　and　photovoltaic　power　generation,　the　importance　of　marine　power　transmission　projects　is　increasing　and　the　application　of　submarine　cables　is　also　becoming　increasingly　widespread.　Accurate　identification　of　the　location　of　submarine　cables　is　not　only　beneficial　for　routine　inspections　but　also　enhances　the　efficiency　of　fault　detection.　Therefore,　the　routing,　positioning,　and　fault　detection　of　submarine　cables　will　play　a　crucial　role　in　future　repair　and　maintenance　operations.　The　small　diameter　of　submarine　cables　and　the　variability　of　internal　currents　have　led　to　a　decrease　in　positioning　accuracy　and　an　increase　in　positioning　difficulty.　To　address　the　aforementioned　issues,　this　paper　first　derives　the　approximate　equation　for　the　external　magnetic　field　of　submarine　cables　based　on　the　underwater　environment　and　underwater　robotics,　utilizing　the　cable　structure　of　three-core　armored　submarine　cables.　The　underwater　robotic　system　performs　attitude　adjustments　based　on　the　detected　magnetic　induction　intensity　values.　Building　upon　this,　a　submarine　cable　positioning　algorithm　is　proposed　using　an　improved　grey　wolf　optimization　(IGWO)　algorithm.　The　algorithm　utilizes　a　fitness　function　based　on　the　magnetic　flux　density　model　and　incorporates　an　online　path　localization　method　specifically　designed　for　submarine　cable　detection.　Finally,　the　accuracy　and　effectiveness　of　the　IGWO　algorithm　are　validated　through　simulation　experiments.　©　2025　Northeast　University.　All　rights　reserved.