Herein,　the　statistical　process　control(SPC)　technology　based　on　the　traditional　＂double-control＂　indicator　analysis　method　is　introduced　and　modified　to　scientifically　analyze　metro　monitoring　data.　The　significance　level　of　the　hypothesis　test　(α　=　0.27%)　corresponding　to　the　3σ　criterion　of　the　SPC　is　low　according　to　the　Chinese　cardinal　engineering　national　code　GB　50068-2018.　Therefore,　the　2σ　discontinuity　identification　criterion　applied　in　civil　engineering　is　proposed　based　on　the　significance　level　α　=5%.　The　proposed　scientific　monitoring　and　analysis　method　for　metro　construction　is　established　by　combining　the　novel　criterion　and　the　SPC　technology.　A　case　study　is　conducted　to　verify　the　feasibility　of　the　proposed　method.　The　results　show　that　SPC　can　fully　utilize　the　monitoring　data　and　analyze　unidentified　data　variations　through　the　traditional　＂double-control＂　indicator　analysis.　The　modified　SPC　outperforms　the　traditional　method　in　terms　of　project　application　and　data　analysis　results.　©　2023　Tunnel　Construction.　All　rights　reserved.