The Shanghai Rail Transit City Line Chongming Line, as a rail transit line quickly connecting Chongming District with Shanghai's central urban area, passes through Pudong New Area, Changxing Island and Chongming Island, and its construction will add strong momentum to Chongming's development. The line starts in the Jinqiao area of Pudong in the south, with a total length of 42.3 kilometers, and has 8 stations, 6 working shafts and 2 depots along the entire line. The 8 stations are: Jinji Road Station (interchange with Line 9), Shenjiang Road Station (interchange with Line 12), Gaobao Road Station, Lingkong North Road Station, Changxing Island Station, Chenjia Town Station, Dongtan Station and Yu'an Station, all of which are underground stations.

The Chongming Line crosses the Yangtze River twice via Changxing Island before finally reaching Chongming Island proper. It is Shanghai's first rail transit line to cross the Yangtze River and also the project with the longest section distance among all river-crossing tunnels in China's rail transit.

Shanghai Metro specially customized two super-large-diameter (cutterhead diameter of 13.5 meters) slurry balance shield machines, which were launched respectively from the two working shafts on the north and south sides located on Changxing Island, crossing the Yangtze River near the river's estuary into the sea.

The "Shentong Hao" shield machine advances toward Pudong to bore the South Port section tunnel, which is 7.739 kilometers long.

On September 12, 2022, the cutterhead of the "Shentong Hao" large shield machine was lowered into the shaft and assembled, and it was launched on December 8, 2022.

The "Shenchong Hao" shield machine advances toward Chongming Island to bore the North Port section tunnel, which is 9.024 kilometers long.

On November 6, 2022, the cutterhead of the "Shenchong Hao" large shield machine was lowered into the shaft and assembled, and it was launched on March 21, 2023.

To ensure the smooth advancement of the two super-large shield machines, Shanghai Metro, through the advanced "Digital Intelligent Tunnel" intelligent control platform, integrates all production elements such as the shield machine wear monitoring system, the in-tunnel traffic control system, and the toxic and harmful gas monitoring, warning and ventilation system, so as to guarantee safe and efficient routine operation of tunnel construction in terms of safety and quality control.

Through the intelligent control platform, adopting a combination of AI monitoring and manual work, automated real-time data collection is achieved for the tunnel's formed quality, key advancement parameters and shield machine attitude, so as to ensure the accuracy of construction parameters, further reduce the probability of hidden dangers, and improve the level of on-site management.

The Chongming Line has currently started construction on 7 stations (Yu'an Station is still in the land acquisition stage), 6 working shafts, 2 depots and 7 running sections. The main structure of 1 station has been capped (Gaobao Road Station), the main structure of 4 shafts has been capped, and 1 running section has been holed through (the section from Changxing Island Station to No. 2 Changxing North Transfer Shaft). Shield tunneling has cumulatively completed 18.0 kilometers (an overall completion rate of 27%), including 7.6 kilometers advanced on the South Port section tunnel (completion rate 98%) and 6.8 kilometers advanced on the North Port section tunnel (completion rate 75%), with another 5 small shield machines currently advancing.