Abstract: The ground interference radar is an effective means for deformation monitoring of water-bearing soil slope to reduce the occurrence of landslide geological disasters, prevent the occurrence of secondary buried pressure, and ensure the life safety of emergency rescue site personnel. In this paper, a radar monitoring accuracy indicator was decomposed into precision and accuracy, and a precision measurement process was proposed based on the analysis of radar monitoring system signal model, related technologies and a self developed portable slope radar system. Some experiments were carried out to verify the system's high-frequency deformation monitoring ability and sub millimeter level monitoring accuracy, and a simulation test of water-bearing soil slope landslide was conducted. The comprehensive analysis of slope surface deformation and precipitation at different time nodes shows that the monitoring curve of surface deformation of water-bearing soil slopes possesses a high similarity to the unstable creep curve of rock and soil mass. Finally, the monitoring application was conducted at the landslide hidden danger point in Eryuan County, Yunnan Province, and the slope deformation trend was analyzed based on the water content data of different strata depths. The research results can provide a strong support for the development and optimization of the safety monitoring and early warning system for water-bearing soil slopes.