When a foundation pit is excavated in high water level,groundwater may cause drift sand and piping failure,even the slope instability or pit wall collapse due to the influent from seepage.Before the excavation of the foundation pit,the common effective way is to reduce the water level inside and outside the foundation pit adopting the light well point dewatering technology.Taking Venice Hengda sea drainage culvert construction engineering culvert excavation as an example,the design of the light well point precipitation scheme and the construction process of concrete is described.