Abstract: The South Anchor of Runyang bridge is a super-deep foundation pit．In this paper, the hydrogeological sub-division is made based on systemic study of the fault，physical characters of rock mass，water abundance，and permeability．Then the numerical simulation of the pit discharge an d uplift pressure were conducted with M ODFLOW software．The simulated results indicate that the discharge would not induce tragically water bursting in the process of engineering excavation if the aquifer of Quaternary is excluded by using underground continuous wall or artificially ground freezing ．But the effect of uplift pressure on the foundation stability should be considered because uplift pressure will affect the engineering stability of the South Anchor excavating directly．W e propose to solve the problem by using drainage holes ．Drainage orientation．Drainage depth an d drainage availability are discussed．