With　the　application　of　Global　Positioning　System　(GPS)　technology　using　in　the　field　of　modem　transport,　more　and　more　long-span　bridges　have　set　up　the　UPS　system　to　monitor　the　real-time　deformation　in　safety　monitoring　system.　Nowadays　the　highest　measuring　accuracy　of　UPS　technology　achieves　millimeter,　and　the　sampling　frequency　can　reach　20Hz.　It　can　solve　real-time　deformation　data　and　adapt　to　the　complexity　and　poor　working　environment.　Based　on　the　application　of　UPS　technology　using　in　long-span　bridges　safety　monitoring　system,　this　paper　set　the　Huangpu　bridge　as　the　engineering　project　and　demonstrate　how　to　apple　the　GPS　technology　in　deformation　monitoring　and　security　evaluation.