Take　the　variation　law　of　internal　force　and　deformation　of　mixed-supporting　system　for　research　target,　base　on　some　deep　foundation　pit　dug　by　Open　Cut　Method,　by　the　method　of　field　monitoring,　the　displacement,　anchor　stress,　supporting　axial　force　of　the　supporting　structure　and　some　problems　occurred　during　the　construction　are　analyzed.　The　main　conclusions　in　this　thesis　have　been　summarized　as　follows:　a)　the　displacement　of　pile　top　and　pile　body　reached　to　the　maximum　when　dug　to　the　bottom　of　foundation　pit.　The　maximum　displacement　occurred　at　the　position　of　6　m-upper　part　of　foundation　pile;　b)　With　the　excavation　of　foundation　pit,　the　cable　stress　rise　in　wave-like　change,　the　temperature　and　construction　loads　is　the　reason　for　cable　stress　showed　wavy　change;　c)　the　displacement,　anchor　stress,　supporting　axial　force　of　envelope　have　obvious　synchronization　with　the　depth　of　excavation,　monitoring　data　is　stable　overall,　the　mixed-supporting　structure　for　the　deep　foundation　pit　is　secure.