Abstract: There are many large rivers in China. Under the conditions of internal soil properties and external rainfall discharge, soil and water exchange occurs between soil and river flow on the bank slope, which leads to the instability and slip on the bank slope easily. Many riverbank slopes are binary riverbank structures dominated by silty sand soils, which have prominent security and stability problems. By taking part of the silty sand reaches of the Xiangjiang River as the research object, this paper uses the finite difference software FLAC3D, based on the fluid-solid coupling theory and strength reduction method, combined with the silty sand bank slope topography and soil data of the selected river reach, Rayno protective structure is proposed. A three-dimensional model of bank slope protection is established to study the influence of Raynaud gaspe-Gabion cage structure protection on bank slope stability from the aspects of bank slope stress field, displacement field, shear strain increment and safety factor. Raynaud’s pad produces a large compressive stress on the bank slope soil due to its own weight, which weakens the soil tension, but has no significant effect on the soil stress distribution. The revetment scheme has an obvious protective effect on the horizontal displacement of the bank slope, the maximum displacement is reduced from 0.61 m to 0.19 m, the vertical displacement of slope foot is reduced from 0.17 m to 0.03 m, and the vertical settlement displacement of slope top is reduced from 0.28 m to 0.07 m. Under the protection of Rayon’s pad, the range of shear strain increment of the bank slope is significantly reduced, the effective plastic strain zone is significantly less than that of the unprotected bank slope, and the maximum value of shear strain increment is also smaller than that of the unprotected bank slope, the shear stress of the soil mass is weakened, and the maximum area appears at the foot of the slope and the junction between the silty sand soil layer and the sandy mudstone basement. In this case, the safety factor of the bank slope reaches 1.549. The protective effect is obvious. The safety factor of the bank slope increases with the increase in the laying length of the Rayon pad. When the laying length reaches the boundary between the silty sand soil layer and the clay layer, the Fs value has reached 1.549, which fully meets the protection requirements. When the laying length continues to the top, the safety factor is stable around 1.58. At this time, the protection effect has met the needs of the project. Through simulation, the protection effect of Renault pad scheme on the bank slope under extreme low water level is obvious, and the stability of the bank slope is significantly improved, indicating that the protection scheme is feasible. Moreover, the laying of Renault pads and Gabion cages is easy to operate, good anti-impact performance, long service life, and does not require regular maintenance and maintenance. The protective structure scheme is suitable for the bank slope.