To research the strength and deformation characteristics of K₀ consolidation saturated silty clay under principal stress axis rotation conditions，a series of directional shear triaxial tests were carried out by using the GDS triaxial test system. The stress vs. strain development law and non-coaxial phenomenon of K₀ saturated silty clay under different principal stress direction angle was researched. The results show that the deformation of K₀ consolidation saturated silty clay mainly performs as the axial compression deformation and its shear strength increases with the principal stress direction angle increasing when b is smaller than 45°. The deformation performs as torsional shear deformation when b is equal to 45°. The axial deformation performs as the dilatancy deformation and the radial deformation performs as the extrusion shrinkage deformation when b is larger than 45°

And its shear strength decreases with the principal stress direction angle increasing. The maximum shear strength of soil appears at b equals to 60°but not at the pure torsion shear test which b equals to 45°. The strength envelope performs as parabola types on the  plan. Test results show that the stress vs. strain curves of K₀ consolidated silty clay obviously performs as non-coaxial phenomenon except for the pure torsional shear test. The above results provide a scientific reference to research the mechanics and constitutive relation of the K₀ consolidation saturated silty clay under the complex stress path.