Abstract: With the rapid development of urban subways, the requirements for the physical quality of the main structure of the station are getting higher and higher. In the past, when the wooden formwork system was used in the construction of the side wall, it was easy to produce common quality defects such as wrong joints, grout leakage, honeycomb pockmark, waves, and water leakage . Based on this, this article takes the construction of the side wall of the main structure of the subway in a certain city as an example to introduce the design and construction points of the large formwork support for the side wall of the deep foundation pit of the subway. It is of great significance.