Shanghai Metro Line 12 (M2) has a total length of 40.4 kilometers, passes through 8 administrative regions, and has 32 stations all underground. It is the diameter line connecting Shanghai's west and northeast in Shanghai's urban rail transit network, and will become the main line that runs through the axis of "Southwest-Northeast" in the central urban area. Line 12 starts from Qixin Road Station in Minhang District in the west, passes through the six central Shanghai urban areas of Xuhui District, Luwan District, Jing'an District, Zhabei District, Hongkou District and Yangpu District and finally reaches Jinhai Road Station, Pudong New District, the project's end point.

The project is still in progress, providing a large number of machines and labor, and there are many types of reinforced connection sleeves, such as variable diameter, lengthened, upset, etc., and the amount has reached more than 1 million, which lasted more than 5 years.