At present,the alarm value in different areas is determined by the main specification and engineering standard provisions,which adopts the extremely strict unified control standards,but it is difficult and uneconomical for the project construction.In this paper,through statistical analysis of monitoring data obtained from the construction process of foundation pit engineering in the southeast coastal area,some suggestions are proposed the aspects of retaining structure horizontal deformation on monitoring alarm value set.The results would provide reference for future engineering safety monitoring.Based on the safety of projects,it reduced successfully many unnecessary alarm events.