In this paper, we aim at obtaining the deformation law and the mechanics characteristic of the supporting structure of ∞-Shaped super deep foundation pit, including the deformation law and the plastic zone of the soil outside the structure. Based on the example of ∞-Shaped super deep foundation pit for South Anchor of the Fourth Nanjing Yangtze River Bridge construction, the full three-dimensional finite element model was used to simulate the excavation of the whole foundation pit. Interaction between the supporting structure and the soil had also been taken into account in calculation. Compared with measured data, the results indicate that traditional design is conservative when applied in the design of ∞-shape super deep foundation pit in account of space effect and arching effect, and the simulated model considering friction between the supporting structure and the soil reflects the soil pressure accurately.