The viscous effect of soil is often neglected in deep foundation pile support design, which is not consistent with the engineering reality in the area where the clay soil is widely distributed. There is no specific study on the accidental deanchoring phenomenon after the anchor cable construction. Based on the Kelvin viscoelastic foundation model, finite element simulation of the particular deep foundation pile support process was carried out to analyze the influences of deanchoring effect on the deformation time effect of the support pile in the support structure under the consideration of viscous hysteresis effect, and the influence range of anchor cable failure with and without considering the crossbeam. The results show that the dense hysteresis effect can play a specific role in delaying the deformation, internal force change, and anchor cable force change of the supporting pile; considering the crossbeam can also effectively inhibit the development of the deformation of the structure in the horizontal direction, and can effectively improve the bending resistance of the supporting pile body, and has a significant protective effect on the structural deformation when the deanchoring occurs.