This paper focuses on the problem of the 1# and 2# aqueducts in the sliding sec-tion of the Huaipai Yellow River water diversion project, which were damaged due to the reactivation of the ancient landslide body. A stability analysis of the initial state of the slope was conducted. The Midas GTS NX and FLAC3D joint modeling method was adopted: the geological CAD drawings were sorted out, the surface and solid models were established through Midas, and after cutting the sliding body, it was imported into FLAC3D. Based on the Mohr-Coulomb cri-terion, boundary constraints and gravity loads were applied for numerical sim-ulation. The results showed that the maximum horizontal displacement was 3.9 cm (in the middle-upper part) and the maximum vertical displacement was 4.95 cm (in the middle-upper part of the sliding body); the surface was mainly under tensile stress, and the absolute value of the bottom compressive stress increased with depth; the maximum shear strain increment was small; the slope stability coefficient was 1.48. The conclusion indicates that the slope as a whole was in a stable state in the initial state.