The　flow　of　essential　elements　such　as　people,　goods,　and　information　through　complex　networks　has　become　a　critical　factor　in　shaping　urban　dynamics　and　regional　development.　Quantifying　location　centrality　plays　an　indispensable　role　not　only　in　urban　infrastructure　planning　but　also　in　National　central　city　planning.　Two　vital　aspects　should　be　considered　for　central　nodes　in　flow-based　complex　networks:　their　impact　on　adjacent　nodes　and　the　diversity　of　nodes　they　affect.　In　this　paper,　we　present　a　centrality　measure　index　(C-index)　that　accounts　for　flow　volume　and　flow　directions,　offering　a　high　degree　of　interpretability.　We　applied　the　C-index　to　four　public　weighted　complex　networks,　demonstrating　that　our　method　outperforms　classical　methods.　Furthermore,　we　validated　the　effectiveness　and　advantages　of　C-index　on　quantifying　location　centrality　both　in　inter-city　and　intra-city　population　mobility　network.　The　centrality　findings　from　the　perspective　of　population　mobility　can　reinforce　guidelines　for　understanding　National　central　cities　and　polycentric　structure　of　cities,　thereby　facilitating　policy-making　of　sustainable　urban　development.