Due to the large scale and rapid occurrence of dip slope disasters, it often causes serious loss of life and property. Addition, in recent years, extreme weather has caused high frequency and heavy rainfall, and the disaster risk of dip slope sliding has also increased. The Taipei City Government actively conducts safety warnings and management of slopes to reduce the occurrence of sloping disasters. Since groundwater is often the main hazard factor for large-scale collapses, it has a great impact on the slope stability. This paper collects the monitoring data of automatic and self-recording water level gauges added in recent years in the large land, and selects a case slope to use the infinite slope theory, Finite element method, linear reservoir and other models are used to study the monitoring alert value of groundwater level monitoring.