Abstract: Reasonable layout of prestressed anchor cable anchorage monitoring points is an important means to improve the reliability of slope stability monitoring.While ensuring the stability and safety of slopes，engineering monitoring costs can be saved to the greatest extent.At present，the monitoring and layout scheme design of the prestressed anchor cable anchorage monitoring points relies on engineering experience，which has strong blindness and high monitoring cost.Especially for large-scale and high-steep slopes，due to the large amount of excavation and the amount of reinforcement work for slopes，how to realize the economical and efficient layout of prestressed anchor cable anchorage monitoring points of high-steep slope and ensuring safe and efficient monitoring of slopes is an issue that is urgently needed to be solved.Aiming at this problem， this paper takes a high slope of Yingbin West Road in Jiangmen City，Guangdong Province as the study background， and determines the reasonable layout distance between the monitoring points by studying the group anchor effect of anchor cables and the influence range of anchor cables after failure.By constructing the three-dimensional model of the slope and the numerical calculation， the whole process of high slope excavation is simulated.The potential dangerous area of deformation instability during slope excavation is analyzed by numerical calculation results， and the selective layout of monitoring points is carried out.Based on the above two methods，the economical and efficient layout of the prestressed anchor cable anchorage monitoring points of the high-steep roadside slope is realized.The study results show that based on the group anchor effect and three-dimensional numerical simulation method，the proposed comprehensive layout optimization scheme for the reasonable layout of prestressed anchor cables and the key monitoring of potential danger areas in the excavation process can rationally utilize materials and space and greatly save monitoring costs，and achieve economic and effective monitoring of slopes.The study results provide a new idea for the reasonable deployment of high-steep roadside slope stability monitoring points.

Key words: Slope stability monitoring, Prestressed anchor cable, Monitoring points, Reasonable layout, High-steep slope