Abstract: It is an important goal of national mine safety supervision to realize the identification and monitoring of major safety risks in key areas and key links of open-pit mines.Based on the actual needs of safety identification and monitoring of tailings dam and dump slope in open-pit mines,the Lanxian-Loufan iron mine area in Shanxi Province was taken as the re search area.A total of 92 small baseline interference pairs composed of 35 scenes of Sentinel-1A SAR data were used.Based on the DS-InSAR technology of distributed scatterers,the effectiveness and applicability of this technology applied to the monito ring of mountain surface deformation in regional open-pit mines were verified,and the surface deformation characteristics of tailings dam and dump slope in this area were analyzed and studied.The monitoring results show that the DS-InSAR technology can effectively identify the surface deformation of three tailings dams and three dump slopes in the study area.Considering that these tailings dams and dumps are in the operation stage,the surface deformation is mainly consolidation subsidence and self compacting deformation.Compared with SBAS-InSAR technology,the coherence of target points is significantly improved after phase optimization and reconstruction of DS-InSAR technology.The number of coherent points increases to 6.5 times,and the correlation coefficient of surface deformation is 0.81.It provides technical and data support for the identification of surface de formation hazards and stability evaluation of tailings dam and dump slope,as well as the study of surface deformation mecha nism.The research shows that Yuanjiacun Iron Mine and Jianshan Iron Mine urgently need to strengthen the normalized moni toring of surface deformation of tailings dam and dump slope.

Key words: DS-InSAR,deformation monitoring,tailings dam,dump slope