Abstract:In order to effectively control the construction process and maintain the stability of deep foundation pit excavation, and based on the engineering practice of Zhenggou station demolition and reconstruction project in Cihuai Xinhe irrigation area, this paper brief1y describes the monitoring principle and content of deep foundationpit construction process. According to relevant codes and engineering experience, the early warning threshold of monitoring data in deep foundation pit construction is proposed and applied.There has obvious effect to handled in time the abnol rnal conditions of slope and surroundding environment during construction.It can provide the technical support and reference for construction safety and management.