Abstract: The non-uniform input of ground motion has a significant effect on the dynamic response of a concrete cut-off wall in deep overburden. In order to explore the response characteristics of the cut-off wall under non-uniform ground motion input at the overburden site， this study establishes the input method of P-wave three-dimensional oblique incident wave motion under any incident angle in space based on the wave field decomposition method and the viscoelastic artificial boundary method， and validates the input method. Nine non-uniform input conditions were designed to investigate the influence of different azimuthal and oblique incidence angles on the dynamic response of the cut-off wall under a combination of incidence. The results show that the maximum acceleration in the down-river direction of the cut-off wall at α=60° and γ=0° incidence is 3.89 times that of vertical incidence， and the maximum acceleration in the axial direction of the dam at α=60° and γ=90° incidence is 8.93 times that of vertical incidence. Non-uniform input causes a significant increase in the transverse riverward tensile stresses in the impermeable wall， up to 3.53 times that of the vertical incidence， with a significant change in the peak distribution region， and the vertical compressive stresses are significantly reduced at an oblique incidence angle of 90° incidence compared to the vertical incidence. The traditional vertical incidence method can ignore the expansion area of tensile stress of the cutoff wall under non-uniform input， so the non-uniformity of ground motion should be considered when analyzing the dynamic response of the cutoff wall in a deep overburden layer.