Guanjiao tunnel, with a total length of 4000 meters, is located in Wulan county and Tianjun County of Qinghai Province in the West (Ninghe) (Ermu) section of Qinghai Tibet railway. Guanjiao tunnel is the longest tunnel at high altitude in the world and the longest tunnel in China. The tunnel structure is composed of two separate single track tunnels, with a total length of 32.46 double kilometers. Due to the complex geology of Guanjiao tunnel, the tunnel construction must pass through the geological fault and Erlang tunnel fault bundle, which is known as the geological museum in the history of tunnel construction. Its completion will prove that China has entered the ranks of the world's high-altitude extra long tunnels.