Jinping auxiliary twin tunnel consists with two lines, one (Line A) is parallel to the other (Line B) with a separation of 35m from center to center, and the length of single line is 175 km. Due to the complex geological environment, there is no suitable condition to build any shaft (vertical or oblique shafts) in between, and the tunnel has to be constructed with bi-directional drilling (eastern and western side). At the meanwhile, as construction field of the western side is insufficient to the requirement for rail transportation, jet ventilation technology applied in highway tunnel operation was introduced for trackless transportation to solve ventilation problem, and air quality indexes was up to the national sanitation standard.