Abstract: A series of bi-directional cyclic dynamic triaxial tests were carried out using red clay backfill of a highway in Nanning as a practical engineering application scenario. The deformation behavior of disturbed red clay under cyclic loading was investigated, and the influence laws of confining pressure, CSR and loading frequency on the dynamic elastic modulus of the soil were analyzed. Hysteresis curves and ε_p-N relationship curves are plotted based on the test results, and the development and evolution rules of soil′s elastic and permanent strains are specifically examined. The results show that after a certain number of cycles, the shape of the stress-strain hysteresis curve of the soil sample basically remains unchanged, so the elastic modulus tends to be stabilized. The decay rate of the resilient modulus of the soil is positively correlated with the confining pressure and the size of the CSR. Additionally, the resilient modulus shows a nonlinear decay trend with the increase of the number of cycles in a fast and then slow manner. The permanent strain of soil samples is significantly affected by the confining pressure, CSR, loading frequency. With the increase of confining pressure, CSR and loading frequency, the rate of permanent strain accumulation increases, producing greater deformation. However, with the increase of the number of cycles, the permanent strain curve gradually converges and the strain stabilizes. Combined with the permanent strain curves, the permanent strain prediction equations satisfying the stable and critical types were established to better predict the cumulative plastic deformation of different deformation states of the remodeled red clay. The test also confirmed the viability of the cumulative deformation model and led to an analysis of the model parameters that yielded the influence law of the cyclic loading conditions on the model parameters. The purpose of this test is to give a theoretical foundation for the dynamic stability analysis of slopes under short-term loading and unloading, as well as a basic reference for the forecast work and safety evaluation of the settlement of the building site.