Abstract: Taking the L-shaped ultra-deep foundation pit of Hongtang Road interchange station of Fuzhou Metro as the engineering background, the excavation and supporting process of the ultra-deep foundation pit is simulated by Midas GTS finite element software, and the horizontal displacement, internal support axial force and land subsidence of the enclosure structure at the interchange node are comprehensively analyzed. Simulation results show that it is feasible to optimize the original 7-lane internal support to 5-lane internal support at the interchange node. The numerical simulation results and the field measured data from the engineering application process are compared and analyzed. Research results show that it is safe and feasible to adopt the support scheme of partition+5-lane internal support for the ultra-deep foundation pit of interchange station, and the horizontal displacement value, internal support axial force value and land subsidence value of the diaphragm wall all meet the specification requirements.