The cyclic load caused by the ship traveling wave is one important reason which leads to the instability of inland waterway revetment，thus it has significance to study the mechanism of soil instability and failure under cyclic load for the design of inland waterway revetment. Plant revetment protection technology can enhance the soil strength by the root combining closely with soil. Based on the remolded plain soil and remolded root reinforced soil of Naji Reservoir，we apply the triaxial cyclic loading test，simulate the long-term action of ship traveling wave load，study the relationships of cyclic loading vibration time，strength，confining pressure strength and soil strain of remolded plain soil and remolded root reinforced soil under cyclic loading. The results show that the residual strain of remolded plain soil and remolded root reinforced soil increases with the increase of cyclic load under different confining pressure. Under the same cyclic load，the internal friction angle and cohesion of remolded root reinforced soil are higher than these of remolded plain soil，and the existence of root improves the resistance effect of soil to ship traveling wave，and improves the shear strength of soil under the cyclic load.