Abstract:The goaf of coal mine in Guizhou has the characteristics of wide distribution, large influence scope, special topography and topography, complex mining scale and so on. While the subsidence and deformation of common goaf has great harm to the transmission line tower and foundation. Therefore, to investigate the influence of goaf on the power transmission lines and to renovate it by proper and economic and high efficiency method have very important significance for the secure and steady operation of power system. Based on the engineering practice in recent years, this paper puts forward the plan of preventing the collapse of goaf by using the Straight column flexible slab foundation, and emphatically analyzes the optimization design, theoretical calculation and precautions of the foundation scheme, so as to achieve the purpose of safety, environmental protection and economic design. At present, the scheme of the Straight column flexible slab foundation has been applied in many transmission line engineering practice above the goaf.