Terrain and climate in Sichuan province's mountains are complex, hence the icing condition of of power network is diversified. So, an investigation on the type and state of icing of transmission lines in typical areas like Daqing-ridge, Yak Mountain and Erlang Mountain in southwest of Sichuan Province is carried out in this paper, as icing phenomenon varied a lot there for its diversiform terrain and climate. It is found that the terrain has a significant impact on the type of icing,the icing type of Yak Mo...