To　address　the　issue　that　the　phasor　measurement　units　(PMUs)　of　wide　area　measurement　system　(WAMS)　are　not　sufficient　for　static　state　estimation　in　most　existing　power　systems,　this　paper　proposes　a　mixed　power　system　weighted　least　squares　(WLS)　state　estimation　method　integrating　a　wide-area　measurement　system　and　supervisory　control　and　data　acquisition　(SCADA)　technology.　The　hybrid　calculation　model　is　established　by　incorporating　phasor　measurements　(including　the　node　voltage　phasors　and　branch　current　phasors)　and　the　results　of　the　traditional　state　estimator　in　a　post-processing　estimator.　The　performance　assessment　is　discussed　through　setting　up　mathematical　models　of　the　distribution　network.　Based　on　PMU　placement　optimization　and　bias　analysis,　the　effectiveness　of　the　proposed　method　was　proved　to　be　accurate　and　reliable　by　simulations　of　different　cases.　Furthermore,　emulating　calculation　shows　this　method　greatly　improves　the　accuracy　and　stability　of　the　state　estimation　solution,　compared　with　the　traditional　WLS　state　estimation.