Deformation monitoring is an important means to monitor the safety of deformation, and the basic function is to collect dynamic displacement information through deformation measurement. According to the information, analysis and determination can be made on early-warning to dangerous situations. Analysis was made on F testing method of stability of basic benchmark of GPS deformation monitoring study. Based on the sliding monitoring engineering in Yunyang County, analysis on stability of basic benchmark of GPS landslide deformation monitoring networks was also made.