【Objective】Rainfall can alter the movement of water in the soil of landslide-prone slopes, affecting the types and concentrations of ions in various soil layers, thereby influencing ion-interface reactions on soil particle surfaces. Additionally, moisture accumulation can exert high permeability pressure on the underlying soil layers, making them prone to deformation and instability. Soil with weaker resistance to permeability pressure, when closer to the surface, is more susceptible to soil erosion. Previous research has mainly focused on the influence of soil water stability and mechanical stability on landslide erosion, however, the impact of ion-interface reactions based on ion characteristics on the permeability characteristics of landslides is not well understood. 【Method】This study focused on the red soil layer of a typical landslide in Anxi County and used ion solutions with different valences and concentrations to manipulate ion-interface reactions on the soil particle surfaces and analyzed their effects on the permeability characteristics of the landslide""s red soil layer. 【Result】K+ reduced soil porosity and decreased the soil""s permeability and conductivity, while Mg2+ increased soil porosity and enhanced the soil""s permeability and conductivity. There was a good single exponential increasing relationship between the permeability coefficient and the electrolyte concentration, with the fitting equations for various consolidation pressures expressed as k = ae-x/t + b, R2 > 0.845, P < 0.1. Also, K+ increased the electrostatic repulsion between soil particles, resulting in net repulsion forces between them, while Mg2+ reduced the electrostatic repulsion, leading to net attraction forces between soil particles. Higher electrolyte concentrations have a more significant impact on altering the internal forces within the soil. 【Conclusion】Ion-interface reactions based on differences in ion characteristics can influence the internal forces of the soil, causing some degree of structural changes in landslide-prone soil.