Changchun is located in Northeast China. Its winter is cold and long, with the lowest temperature reaching -35℃. Such extreme climatic conditions impose strict requirements on the embedded channels, cable supports and other electromechanical supporting products in metro projects - they not only need to have excellent anti-corrosion, anti-freezing and anti-aging performance, but also need to meet the installation requirements of different scenarios such as metro tunnels and stations. At the same time, it takes into account both the construction efficiency and the convenience of later operation and maintenance. As the "golden corridor" connecting the east and west of the city, the quality of the mechanical and electrical installation works of Changchun Metro Line 2 directly affects the safety and durability of the line's operation. Therefore, during the supplier selection process, the construction company, Changchun Metro Co., LTD., conducted a strict review of the materials, performance, technical standards of the products and the company's service capabilities.