Abstract: To study the engineering properties of red clay modified by sodium polyacrylate, the Liuzhou remodeled red clay cured by sodium polyacrylate was selected for the permeability test with variable head and triaxial shear test to analyze the permeability and mechanical properties of the modified red clay and to determine the optimum amount of sodium polyacrylate. The disintegration resistance and microscopic mechanism of the modified red clay were determined by the disintegration test and scanning electron microscope test, respectively. The results show that the permeability coefficient of the modified soil decreases gradually with the increase of sodium polyacrylate, and gradually stabilizes after reaching 3% with the permeability coefficient of 8.1379×10⁻⁷ cm/s, 90.78% lower than that of the plain soil. In contrast, the shear strength of the modified red clay shows an increasing trend firstly, then decreases, and then keeps stable at at 2%, which is 394.21% higher than that of the plain soil. The optimal dosage is 3%, and in such situation, the anti-disintegration performance of the modified soil is improved by 42.86%. The pores between the soil particles filled by polymer chains lead to the continuous fragmented granular red clay . The arrangement structure and denseness are better than those of the plain red clay. The impermeability, mechanical properties, and disintegration resistance of the red clay modified by sodium polyacrylate are significantly improved. This study can provide theoretical information for the practical engineering.