Parking　management　is　an　important　part　of　urban　management.　Accurate　Global　Positioning　System　(GPS)　points　of　parking-slots　are　the　core　of　various　applications　ranging　from　looking　for　vacant　parking-slots　to　designing　the　parking　policies.　Affected　by　high-rise　buildings　and　various　signals,　either　blocked　or　affected　GPS　points　tend　to　mismatch　the　actual　locations.　Therefore,　due　to　the　large　number　of　parking-slots,　it　is　not　a　trivial　problem　to　correcting　raw　GPS　points　in　a　unsupervised　approach.　In　this　paper,　discovering　that　the　parking-slots　always　most　parallel　with　the　roads　in　a　city,　we　proposes　an　unsupervised　low　rank　method　to　effectively　correct　GPS　points　of　the　parking-slots　by　rotating-translating-aligning　operations.　The　proposed　method　theoretically　handles　any　errors　of　GPS　points;　besides,　the　proposed　unconventional　alignment　method　is　simple,　yet　effective　and　efficient　for　large-scale　points　for　a　city.　Extensive　experiments　demonstrate　the　superiority　of　the　proposed　method.　©　2022　IEEE.