Abstract: The monitoring results of the internal force and displacement of support structure for a subway deep excavation are analyzed.The prestress loss of the anchor is in the range of 10%～25%, with about 10% increase in the axial force of the anchor during the construction. The axial force of steel prop increases with the increment of the excavation depth. And the value changes with the variety of excavation mode, velocity and dismantlement of the underlying props in order. The horizontal displacement of the retaining pile body is related to the pile depth and supporting condition. The deformation of the earth surface is the largest in the middle and the smaller at the end.