Since reform and opening up, all walks of life enter rapid economic development, demanding for electricity is in the rising trend, so it is very necessary for stable and reliable supply of electricity. Power grid construction is accelerated constantly in recent years, which also lead to the speed of the construction of the transmission lines. As an important component of the power grid, due to its long-term exposure to outdoor harsh environment, it is easy for transmission lines to be damaged by external forces, so lightning protection and grounding of the transmission line is very necessary. Power grid transmission line has a wide coverage and they are set in the complex environment conditions, any failure will affect the whole system. Therefore, in the process of power grid stability, maintenance and management is an important link. Transmission line lightning protection is an important content in line work. In order to prevent damage due to lightning strike, the design of the lightning protection grounding for transmission lines is necessary. The reason and harm of the transmission line lightning, lightning protection and the kinds of main technical measures are analyzed in the paper. This paper further introduced the transmission line lightning protection grounding technology, as well as the existing problems and modification methods of grounding systems located in soil.