In order to solve problems of land shortage and transmission line construction in the old urban area，taking the underground goaf of Xiuwu North power transmission substation as the research object，on the basis of clarifying the basic geological conditions and mining conditions of the underground goaf of the transmission substation，SBAS-InSAR monitoring was used to study the development characteristics of surface subsidence. The evolution characteristics of surface subsidence of the transmission line through the mining right area were quantitatively analyzed. The influence of goaf settlement，inclination and curvature on the transmission line of the substation was evaluated. The results show that the maximum average settlement rate of the surface of the study area is -53.6 mm/a，and the location of this area coincides with the location of Guhanshan mine，and the subsidence is consistent with coal mining，and the settlement rate of the tower position is between -16.5--0.3 mm/a. The average settlement rate of No. 11 and No. 35 towers are significantly greater than those of other positions，with the average settlement rates of -15.88 and -16.21 mm/a respectively. The historical tracing of the deformation law shows that the maximum cumulative subsidence occurs at the end of the monitoring period，which is -104.91 and -106.97 mm respectively. According to the most unfavorable principle，it is concluded that the actual monitoring and predicted settlement of the unfavorable points of the interannual deformation rate of the tower in each region during the service life is less than 400 mm，and the maximum inclination and curvature of the tower are 1.2 mm/m and the curvature is 0 mm/m²，which are all within the specified minimum allowable value. The surface of the transmission line crossing the mining rights area is in a safe and stable state.