At around 9am on June 26, 2026, a muffled sound came from deep inside the Wumeng Mountain. The Zhaotong Tunnel, which is buried nearly a kilometer underground and has a total length of 16.26 kilometers, has its last rock wall pierced through. For this day, the builders spent nearly two years crossing 9 layers of protruding coal seams, resolving karst water inrush and large deformation of soft rocks, and gnawing down this Grade I high-risk tunnel that integrates coal and gas outbursts, strong karst development, high ground stress, and other complex geological factors. It is the last tunnel on the entire Chongqing Kunming high-speed railway line, and its completion means that all tunnels along the line have been opened.

The last tunnel was drilled through

The Chongqing Kunming high-speed railway is an important component of the national eight vertical and eight horizontal high-speed railway network, the Beijing Kunming corridor, and also the first major corridor in the southwest region that connects Sichuan, Chongqing, and Yunnan. The line starts from Chongqing West Station, passes through four provinces and cities including Chongqing, Sichuan, Guizhou, and Yunnan, and ends at Kunming South Station. The total length of the main line is about 700 kilometers, with 21 stations and a designed speed of 350 kilometers per hour. It is the first high-speed railway in Yunnan with a designed speed of 350 kilometers per hour. At the beginning of the planning, the route was divided into the Chongqing Yibin section and the Yibin Kunming section for implementation. The Chongqing Yibin section has been completed and opened to traffic, while the Yikun section is under construction.

The geological difficulty can be seen from the figures: the line in Yunnan runs through the hinterland of Wumeng Mountain in the the Yunnan-Guizhou Plateau, with a bridge tunnel ratio of 87.4% and 10 long tunnels exceeding 10 kilometers. At present, the main offline projects such as roadbed, bridges, and tunnels in Sichuan have been basically completed, and the station building and four electrical engineering are expected to be completed by October 2026; All 53 tunnels in the Yunnan section have been completed, and control projects such as the Luoze River Grand Bridge will be completed within this year.

Steel rails laid towards Spring City

The track laying project has started in mid-2026. The track laying of the section from Yibin to Yanjin South started on May 8th and was completed on June 3rd; Yanjin South to Kunming South are currently in the final sprint due to the impact of some tunnel progress. As of now, the main line has completed 566.65 kilometers and the remaining 151.98 kilometers are progressing in an orderly manner.

A bidding announcement reveals a clearer timetable. On October 9th, Beijing Kunming High speed Railway Xikun Co., Ltd. issued a bidding notice for dynamic testing and line patrol and security services during the trial operation of the Yibin Kunming section of the new Chongqing Kunming high-speed railway. The planned construction period is tentatively from December 17, 2026 to April 30, 2027. This means that the construction phase is coming to an end and is about to enter the stage of static acceptance and dynamic testing. Based on this, it is highly likely that the line will be completed and pass static acceptance by the end of this year; According to the preliminary schedule, the Yibin Kunming section of the Chongqing Kunming high-speed railway is planned to be opened in June 2027. Of course, the exact time of railway opening cannot be predicted, and the actual opening shall prevail.

2.5 hours of new time and space

After the opening of the road in the first half of next year, the travel time from Chengdu to Kunming will be reduced to 3 hours, while the travel time from Chongqing to Kunming will only be about 2.5 hours. In the initial stage of planning and opening, 57 pairs of trains will be operated daily, with an average of one train every 16 minutes. Later, it can be increased to 110 pairs.

The significance of this 350 high-speed railway goes beyond speed. It will completely connect the entire 350 high-speed railway line from Beijing to Xi'an, Chongqing to Kunming, directly linking the Chengdu Chongqing urban agglomeration and the central Yunnan urban agglomeration, allowing more than 10 high-speed blind spots along the line, such as Gao County, Yunlian, Yiliang, etc., to access the national backbone high-speed railway network. Among the newly built stations in Yunnan, such as Yanjin South, Yiliang North, Zhaotong East, Huize, Tianba, Xundian, Changshui Airport, etc., Changshui Airport Station is located below the terminal building, forming a new pattern of air rail intermodal transportation; It is integrated into the national high-speed railway network to the north, and opens a large channel to connect China Laos railway to the south. Kunming is turning from the southwest transportation terminal to a regional hub.keywords:Engineering infrastructure

This high-speed railway has been in operation for more than ten years, from its first proposal in 2008 to the initial promotion in 2015, and finally to the official approval of the feasibility study report by the state in 2019. June 2027 is only the planned opening date, and the actual progress may also be advanced.Editor/Yang Meiling