The　traditional　low-voltage　distribution　networks　rely　on　manual　records　for　line　data,　which,　due　to　factors　such　as　dispersed　equipment,　frequent　modifications,　and　rapid　topology　changes,　lead　to　low　efficiency　and　high　error　rates,　and　also　affect　the　calculation　of　transformer　area　line　losses　and　fault　section　location.　These　problems　pose　numerous　challenges　to　the　management　and　monitoring　of　low-voltage　distribution　networks.　To　address　these　issues,　this　paper　proposes　a　topology　identification　and　line　length　measurement　method　based　on　power　line　carrier　communication　technology.　The　method　utilizes　carrier　transmission　of　Global　Positioning　System　(GPS)　time　signals　to　achieve　topology　identification　and　line　length　measurement.　Additionally,　the　carrier　propagation　velocity　is　experimentally　fitted　to　improve　the　applicability　of　the　method　to　practical　line　length　measurement.　Experimental　results　demonstrate　that　the　proposed　method　offers　high　accuracy　and　real-time　performance,　significantly　enhancing　the　intelligence　of　low-voltage　distribution　networks,　reducing　manual　operations,　and　improving　operation　and　maintenance　efficiency.　©　2025　IEEE.