为解决地铁换乘站基坑支护工程设计及施工风险问题，通过分析换乘站基坑特点，优化地铁换乘站基坑首层平面轮廓为圆形，运用圆形环框梁抗压性强的特点布置圆形环框梁支撑体系。该体系具有变形易控制、拆撑风险低、工序方便快捷等优点。以广州地铁21号线天河公园站和南通地铁文化公园站为例，验证其实用性，以期为类似工程提供参考。

The design and construction risk are very important to foundation pit supporting of metro transfer station. Hence, the characteristics of foundation pit of metro transfer station are analyzed, the plane outline of first floor of foundation pit is optimized, and the circular ring frame beam supporting system is adopted. The system adopted is characterized by easy control, low dismantling risk, simple construction sequence, etc. The system is applied to Tianhe Park Station on Guangzhou Metro No. 21 and Cultural Park Station on Nantong Metro to verify its practicability. The results can provide reference for similar projects in the future.