Abstract: To study the deformation laws of saturated remolded loess under the rotation of principal stress axis, the cyclic triaxial tests and cyclic traffic load tests on the saturated remolded loess under drainage are carried out by using the hollow cylinder torsional shear apparatus, and the effects of the rotation of the principal stress axis on the vertical plastic cumulative strain, radial plastic cumulative strain and octahedral plastic cumulative shear strain of the saturated remolded loess are mainly studied. The experimental results show that: (1) The rotation of the principal stress axis will cause the plastic cumulative deformation of soil. The vertical plastic cumulative deformation and octahedral plastic cumulative shear strain of soil exhibit a logarithmic growth trend with the increase of the cyclic times, and the cyclic vertical stress ratio and cyclic torsional shear stress ratio are positively correlated with them. At the initial stage of the plastic cumulative strain, it is mainly in the form of tensile strain. With the increase of load times, its value gradually decreases and accumulates in the opposite direction. (2) The rotation of the principal stress axis will accelerate the corresponding vertical plastic accumulated strain. When other conditions are certain, the deformation of the samples under cyclic traffic loads is several times that of cyclic triaxial tests. (3) The vertical deformation of the remolded loess under traffic loads is far less than that of undisturbed soft clay, which has certain advantages as the subgrade filling materials. (4) The existing vertical plastic cumulative strain model is modified, and an explicit prediction model for the settlement deformation of saturated remolded loess is obtained, and the validity of the model is analyzed and verified.