Based on the actual monitoring data of a metro tunnel and Combined with the actual situation in the field of three-dimensional excavation simulation,we'd like to explore the variation of tunnel settlement and deformation in weak rock mass with the coupling of seepage stress. Through the simulation calculation and the actual circumstances of the results, to determine the supporting effect of combined supporting method in the surrounding rock breaking and groundwater seepage.So we can ensure the safety of tunnel excavation and save the excavation period to make an effective assessment.