Abstract: With the dangerous situation of slope instability sliding and support deformation as well as the building subside increasing in the process of a deep foundation pit excavation, the multi-analysis and research ways which are composed of the field hydrogeology character surveying and support structure simulation with construction monitoring data analysis are used in this paper. The main causes which result in slope instability sliding are found the original silt and fine sand layer sedimentation which are strongly sensibility for construction disturbance. The treatment measures using the soil anchorage replaced of the concrete injecting are proposed and successfully applied on the field, which ensure for the deep foundation pit excavating safety and the slope final stabilization.